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wtf-triassic · 5 years ago

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Odontochelys semitestacea

By @alphynix

Etymology: Toothed Turtle

First Described By: Lie et al., 2008

Classification: Biota, Archaea, Proteoarchaeota, Asgardarchaeota, Eukaryota, Neokaryota, Scotokaryota, Opimoda, Podiata, Amorphea, Obazoa, Opisthokonta, Holozoa, Filozoa, Choanozoa, Animalia, Eumetazoa, Parahoxozoa, Bilateria, Nephrozoa, Deuterostomia, Chordata, Olfactores, Vertebrata, Craniata, Gnathostomata, Eugnathostomata, Osteichthyes, Sarcopterygii, Rhipidistia, Tetrapodomorpha, Eotetrapodiformes, Elpistostegalia, Stegocephalia, Tetrapoda, Reptiliomorpha, Amniota, Sauropsida, Eureptilia, Romeriida, Diapsida, Neodiapsida, Sauria, Archosauromorpha?, Archelosauria, Pantestudines, Odontochelyidae

Time and Place: Around 232 million years ago, in the Carnian age of the Late Triassic

Odontochelys is known from the Lower Member of the Xiaowa Formation of China, commonly known as the Guanling Fauna

Physical Description: Odontochelys is one of the earliest known turtles - preceded by one, possibly two, precursors other than stem members of the family group - and it showcases how this extremely unique group managed to evolve in the chaos that was the Triassic Explosion. It was simultaneously similar to and very different from living turtles, a true transitional organism. Like other reptiles, it had teeth embedded in its jaws, rather than the toothless beak found in turtle mouths. Like turtles, it had the lower plastron extending from its ribs, but unlike living turtles it had no upper shell - instead, it just had widened ribs and no bony shell around its body. The ribs and the vertebrae were put together differently from modern turtles as well, and its skull was more stretched out compared to its living relatives. It didn’t have fused tail bones, and its scapulae were very different from living turtles. It had short limbs and long, thick fingers, as well as a decently sized shell. It was about forty centimeters long from snout to tail tip.

Diet: The diet of Odontochelys is fairly uncertain, despite us having its teeth; though they are small and peg like, we can’t really extrapolate a function since we don’t actually know its precise ecology! They may have been used for stripping plants, but it’s also possible they were used to chipp up algae and other aquatic water plants, or even invertebrates! So, more research there is clearly needed.

Behavior: The life history of Odontochelys is actually a big mystery. It was found in a marine environment, leading initial studies to indicate it was marine. However, it had the hands of a fresh water organism, including fresh water turtles today. Furthermore, studies of other early turtles indicate that turtles first arose on the land, rather than in the water, and later groups would adapt to water life; the limbs of Odontochelys share similarities with tortoises and support a terrestrial lifestyle. So, the ecology of Odontochelys has been a constant battle. That said, there is some evidence that it was actually marine - and may represent an early experiment in ocean life by turtles. One fossil of Odontochelys indicates that it had completely messed up shoulder bones, likely due to a problem in life rather than destruction of the fossil. This pattern resembles decompression sickness, aka the bends, aka the condition caused by a diving animal coming up much too fast from a lower depth. Modern turtles have complex behavioral adaptations to avoid the bends, so Odontochelys may be an early experiment in marine life in a group mostly adapted for terrestrial life. In this transition to ocean life, it not only lacked better physical adaptations for the ocean, but also better behavioral ones, and was stricken with the bends on its trip back to the surface. So, as we try to determine its ecology and behavior, these clued paint a rich tapestry of the world’s most transitional turtle. A pioneer!

Ecosystem: Odontochelys was found in - and thus, the null hypothesis is that it lived in - an ocean environment near the coast of the Tethys sea. This was a deep, open ocean - pelagic, hence the bends and problems Odontochelys faced trying to deal with the ocean. It was a very fertile ecosystem as well, with a variety of Triassic marine animals showcasing the rapid evolution of these groups. Among the invertebrates, there were many different types of Ammonites, plenty of bivalves, brachiopods, and crinoids & sea cucumbers as well. Still, the fascinating part of the ecosystem was the sheer number of marine reptiles. There were Thalattosaurs such as Anshusaurus and Xinpusaurus; Placodonts like Psephochelys and Sinocyamodus; and Ichthyosaurs like Qianicthyosaurus, Guizhouichthyosaurus, Guanlingsaurus, and Callawayia. One of many beautiful deposits of marine animals from this Period - and the many Ichthyosaurs would have been major predators of the relative n00b Odontochelys.

Other: Odontochelys also just looks really weird because it basically looks like your usual turtle except it doesn’t have a freaking shell so here we are with this oddity. It’s transitional in shape, transitional in ecology, transitional in behavior, and just. What the heck. What the heck, Odontochelys. If you need more proof for evolution despite knowing about the dinosaur - bird transition, have I got a friend for you.

~ By Meig Dickson

Sources Under the Cut

Anquetin, J. 2012. Reassessment of the phylogenetic interrelationships of basal turtles (Testudinata). Journal of Systematic Palaeontology 10(1):3-45.

Bradley Shaffer, H., E. McCartney-Melstad, T. J. Near, G. G. Mount, P. Q. Spinks. 2017. Phylogenomic analyses of 539 highly informative loci dates a fully resolved time tree for the major clades of living turtles (Testudines). Molecular Phylogenetics and Evolution 115: 7 - 15.

Feldmann, R. M., C. E. Schweitzer, S. Hu, J. Huang, Q. Zhang, C. Zhou, W. Wen, T. Xie, E. P. Maguire. 2017. A new Middle Triassic (Anisian) cyclidan crustacean from the Luoping Biota, Yunnan Province, China: morphologic and phylogenetic insights. Journal of Crustacean Biology 37 (4): 406 - 412.

Gilbert, S. F. 2007. How the turtle gets its shell. Biology of Turtles: The Structures to Strategies of Life.

Heiss, E. 2010. Functionality and plasticity of turtle-feeding with special emphasis on oropharyngeal structures. Universitat Wien Doctoral Dissertation.

Hess, H., W. Etter, and H. Hagdorn. 2016. Roveacrinida (Crinoidea) from Late Triassic (early Carnian) black shales of Southwest China. Swiss Journal of Paleontology 135(2):249-274.

Joyce, W. G. 2015. The origin of turtles: A paleontological perspective. Journal of Experimental Zoology Part B: Molecular and Developmental Evolution 324 (3): 181 - 193.

Lee, M. S. Y. 2013. Turtle origins: Insights from phylogenetic retrofitting and molecular scaffolds. Journal of Evolutionary Biology 26 (12): 2729 - 2738.

Lemell, P., N. Natchev, C. J. Beisser, E. Heiss. 2019. Feeding in Turtles: Understanding Terrestrial and Aquatic Feeding in a Diverse but Monophyletic Group. Feeding in Vertebrates: 611 - 642.

Li, C., and O. Rieppel. 2002. A new cyamodontid placodont from Triassic of Guizhou, China. Chinese Science Bulletin 47(5):403-407.

Li, C., X. C. Wu, O. Rieppel, L. T. Wang, and L. J. Zhao. 2008. An ancestral turtle from the Late Triassic of southwestern China. Nature 456:497-501.

Lu, H., D.-Y. Jiang, R. Motani, P.-G. Ni, Z.-Y. Sun, A. Tintori, S.-Z. Xiao, M. Zhou, C. Ji, W.-L. Fu. 2018. Middle Triassic Xingyi Fauna: Showing turnover of marine reptiles from coastal to oceanic environments. Palaeoworld 27 (1): 107 - 116.

Luo, M., Y.-M. Gong, G. R. Shi, Z.-Q. Chen, J. Huang, S. Hu, X. Feng, Q. Zhang, C. Zhou, W. Wen. 2018. Palaeoecological Analysis of Trace Fossil Sinusichnus sinuosus from the Middle Triassic Guanling Formationin Southwestern China. Journal of Earth Science 29: 854 - 863.

Meredith, R. W., J. Gatesy, M. S. Springer. Molecular decay of enamel matrix protein genes in turtles and other edentulous amniotes. BMC Evolutionary Biology 13: 20.

Neenan, J. M., N. Klein, T. M. Scheyer. 2013. European origin of placodont marine reptiles and the evolution of crushing dentition in Placodontia. Nature Communications 4: 1621.

Nicholls, E. L., C. Wei, and M. Manabe. 2002. New material of Qianichthyosaurus Li, 1999 (Reptilia, Ichthyosauria) from the Late Triassic of southern China, and implications for the distribution of Triassic icthyosaurs. Journal of Vertebrate Paleontology 22(4):759-765.

Reisz, R. R., J. J. Head. 2008. Palaeontology: Turtle origins out to sea. Nature 456 (7221): 450 - 451.

Rothschild, B. M., V. Naples. 2015. Decompression syndrome and diving behavior in Odontochelys, the first turtle. Acta Palaeontologica Polonica 60 (1): 163 - 167.

Schoch, R. R., H.-D. Sues. 2015. A Middle Triassic stem-turtle and the evolution of the turtle body plan. Nature 523 (7562): 584 - 587.

Shang, Q.-H., and C. Li. 2009. On the occurrence of the ichthyosaur Shastasaurus in the Guanling biota (Late Triassic), Guizhou, China. Vertebrata PalAsiatica 47(3):178-193.

Vermeij, G. J., R. Motani. 2017. Land to sea transitions in vertebrates: the dynamics of colonization. Paleobiology 44 (2): 237 - 250.

Wang, X., G. H. Bachmann, H. Hagdorn, P. M. Sanders, G. Cuny, X. Chen, C. Wang, L. Chen, L. Cheng, F. Meng, and G. Xu. 2008. The Late Triassic black shales of the Guanling area, Guizhou province, south-west China: a unique marine reptile and pelagic crinoid fossil lagerstätte. Palaeontology 51(1):27-61.

Wang, X., X. Chen, C. Wang, L. Cheng. 2009. The Triassic Guanling Fossil Group - A Key GeoPark from a barren mountain, Guizhou Province, China. Notebooks on Geology 3: Chapter 2: 11 - 28.

#odontochelys #turtle #triassic #triassic madnes #triassic march madness #prehistoric life #paleontology

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a-dinosaur-a-day · 5 years ago

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Lagerpeton

By Tas

Etymology: Rabbit Reptile

First Described By: Romer, 1971

Classification: Biota, Archaea, Proteoarchaeota, Asgardarchaeota, Eukaryota, Neokaryota, Scotokaryota Opimoda, Podiata, Amorphea, Obazoa, Opisthokonta, Holozoa, Filozoa, Choanozoa, Animalia, Eumetazoa, Parahoxozoa, Bilateria, Nephrozoa, Deuterostomia, Chordata, Olfactores, Vertebrata, Craniata, Gnathostomata, Eugnathostomata, Osteichthyes, Sarcopterygii, Rhipidistia, Tetrapodomorpha, Eotetrapodiformes, Elpistostegalia, Stegocephalia, Tetrapoda, Reptiliomorpha, Amniota, Sauropsida, Eureptilia, Romeriida, Diapsida, Neodiapsida, Sauria, Archosauromorpha, Crocopoda, Archosauriformes, Eucrocopoda, Crurotarsi, Archosauria, Avemetarsalia, Ornithodira, Dinosauromorpha, Lagerpetidae

Referred Species: L. chanarensis

Status: Extinct

Time and Place: About 235 to 234 million years ago, in the Carnian of the Late Triassic

Lagerpeton is known from the Chañares Formation in La Rioja, Argentina

Physical Description: Lagerpeton was named as the Rabbit Reptile, and for good reason - in a lot of ways, it represents a decent attempt by reptiles in trying to do the whole hoppy-hop thing. You might think that it resembles Scleromochlus in that way, and you’d be right! Scleromochlus and Lagerpeton are close cousins, but one is on the line towards Pterosaurs - Scleromochlus - and the other is on the line towards dinosaurs - Lagerpeton. So, hopping around was an early feature that all Ornithodirans (Dinosaurs, Pterosaurs, and those closest to them) shared. Lagerpeton itself was about 70 centimeters in length, with most of that length represented as tail; it was slender and lithe, built for moving quickly through its environment. It had a small head, a long neck, and a thin body. While it had long legs, it also had somewhat long arms, and while it may have been able to walk on all fours it also would have been able to walk on two legs alone. It was digitigrade, walking only on its toes, making it an even faster animal. Its back was angled to help it in hopping and running through its environment, and its small pelvis gave it more force during hip extension while jumping. In addition to all of this, it basically only really rested its weight on two toes - giving it even more hopping ability! As a small early bird-line reptile, it would have been covered in primitive feathers all over its body (protofeathers), though what form they took we do not know.

By Scott Reid

Diet: As an early dinosaur relative, it’s more likely than not that Lagerpeton was an omnivore, though this is uncertain as its head and teeth are not known at this time.

Behavior: Lagerpeton would have been a very skittish animal, being so small in an environment of so many kinds of animals - and as such, that hopping and fast movement ability would have aided it in escaping and moving around its environment, avoiding predators and reaching new sources of food (and, potentially, chasing after smaller food itself). Lagerpeton may have also been somewhat social, moving in small groups, potentially families, to escape the predators and chase after prey together, given its common nature in its environment. As an archosaur, Lagerpeton was more likely than not to take care of its young, though we don’t know how or to what extent. The feathers it had would have been primarily thermoregulatory, and as such, they would have helped it maintain a constant body temperature - making it a very active, lithe animal.

By José Carlos Cortés

Ecosystem: Lagerpeton lived in the Chañares environment, a diverse and fascinating environment coming right after the transition from the Middle to Late Triassic epochs. Given that the first true dinosaurs are probably from the start of the Late Triassic, this makes it a hotbed for understanding the environments that the earliest dinosaurs evolved in. Since Lagerpeton is a close dinosaur relative, this helps contextualize its place within its evolutionary history. This environment was a floodplain, filled with lakes that would regularly flood depending on the season. There were many seed ferns, ferns, conifers, and horsetails. Many different animals lived here with Lagerpeton, including other Dinosauromorphs like the Silesaurid Lewisuchus/Pseudolagosuchus and the Dinosauriform Marasuchus/Lagosuchus. There were crocodilian relatives as well, such as the early suchian Gracilisuchus and the Rauisuchid Luperosuchus. There were also quite a few Proterochampsids, such as Tarjadia, Tropidosuchus, Gualosuchus, and Chanaresuchus. Synapsids also put in a good show, with the Dicynodonts Jachaleria and Dinodontosaurus, as well as Cynodonts like Probainognathus and Chiniquodon, and the herbivorous Massetognathus. Luperosuchus would have definitely been a predator Lagerpeton would have wanted to get away from - fast!

By Ripley Cook

Other: Lagerpeton is one of our earliest derived Dinosauromorphs, showing some of the earliest distinctions the dinosaur-line had compared to other archosaurs. Lagerpeton was already digitigrade - an important feature of Dinosaurs - as shown by its tracks, called Prorotodactylus. These tracks also showcase that dinosaur relatives were around as early as the Early Triassic - and that their evolution, and the rapid diversification of archosauromorphs in general, was a direct result of the end-Permian extinction.

~ By Meig Dickson

Sources Under the Cut

Arcucci, A. 1986. New materials and reinterpretation of Lagerpeton chanarensis Romer (Thecodontia, Lagerpetonidae nov.) from the Middle Triassic of La Rioja, Argentina. Ameghiniana 23 (3-4): 233-242.

Arcucci, A. B. 1987. Un nuevo Lagosuchidae (Thecodontia-Pseudosuchia) de la fauna de los Chañares (Edad Reptil Chañarense, Triasico Medio), La Rioja, Argentina. Ameghiniana 24: 89 - 94.

Arcucci, A., C. A. Mariscano. 1999. A distinctive new archosaur from the Middle Triassic (Los Chañares Formation) of Argentina. Journal of Vertebrate Paleontology 19: 228 - 232.

Bittencourt, J. S., A. B. Arcucci, C. A. Marsicano, M. C. Langer. 2014. Osteology of the Middle Triassic archosaur Lewisuchus admixtus Romer (Chañares Formation, Argentina), its inclusivity, and relationships amongst early dinosauromorphs. Journal of Systematic Palaeontology: 1 - 31.

Brusatte, S. L., G. Niedzwiedzki, R. J. Butler. 2011. Footprints pull origin and diversification of dinosaur stem lineage deep into Early Triassic. Proceedings of the Royal Society B: Biological Sciences 278 (1708): 1107 - 1113.

Ezcurra, M. D. 2006. A review of the systematic position of the dinosauriform archosaur Eucoelophysis baldwini Sullivan & Lucas, 1999 from the Upper Triassic of New Mexico, USA. Geodiversitas 28(4):649-684.

Ezcurra, M. D. 2016. The phylogenetic relationships of basal archosauromorphs, with an emphasis on the systematics of proterosuchian archosauriformes. PeerJ 4: e1778.

Fechner, R. 2009. Morphofunctional evolution of the pelvic girdle and hindlimb of DInosauromorpha on the lineage to Sauropoda (Thesis). Ludwigs Maximillians Universita.

Fiorelli, L. E., S. Rocher, A. G. Martinelli, M. D. Ezcurra, E. Martin Hechenleitner, M. Ezpeleta. 2018. Tetrapod burrows from the Middle-Upper Triassic Chañares Formation (La Rioja, Argentina) and its palaeoecological implications. Palaeogeography, Palaeoclimatology, Palaeoecology 496: 85 - 102.

Kammerer, C. F., S. J. Nesbitt, N. H. Shubin. 2012. The first Silesaurid Dinosauriform from the Late Triassic of Morocco. Acta Palaeontological Polonica 57 (2): 277.

Kent, D. V., P. S. Malnis, C. E. Colombi, A. A. Alcober, R. N. Martinez. 2014. Age constraints on the dispersal of dinosaurs in the Late Triassic from magnetochronology of the Los Colorados Formation (Argentina). Proceedings of the National Academy of Sciences 111: 7958 - 7963.

Irmis, R. B., S. J. Nesbitt, K. Padian, N. D. Smith, A. H. Turner, D. T. Woody, and A. Downs. 2007. A Late Triassic dinosauromorph assemblage from New Mexico and the rise of dinosaurs. Science 317:358-361.

Jenkins, F. A. 1970. The Chañares (Argentina) Triassic reptile fauna. VII. The postcranial skeleton of the traversodontid Massetognathus pascuali (Therapsida, Cyondontia). Breviora 352: 1 - 28.

Langer, M. C., S. J. Nesbitt, J. S. Bittencourt, R. B. Irmis. 2013. Non-dinosaurian Dinosauromorphs. Geological Society London, Special Publications. 379 (1): 157 - 186.

Marsh, A. D. 2018. A new record of Dromomeron romeri Irmis et al., 2007 (Lagerpetidae) from the Chinle Formation of Arizona, U.S.A. PaleoBios 35:1-8.

Marsicano, C. A., R. B. Irmis, A. C. Mancuso, R. Mundil, F. Chemale. 2016. The precise temporal calibration of dinosaur origins. Proceedings of the National Academy of Sciences of the United States of AMerica 113 (3): 509 - 513.

Martz, J. W., and B. J. Small. 2019. Non-dinosaurian dinosauromorphs from the Chinle Formation (Upper Triassic) of the Eagle Basin, northern Colorado: Dromomeron romeri (Lagerpetidae) and a new taxon, Kwanasaurus williamparkeri (Silesauridae). PeerJ 7:e7551:1-71.

Nesbitt, S. J., R. B. Irmis, W. G. Parker, N. D. Smith, A. H. Turner and T. Rowe. 2009. Hindlimb osteology and distribution of basal dinosauromorphs from the Late Triassic of North America. Journal of Vertebrate Paleontology 29(2):498-516.

Nesbitt, S. J. 2011. The early evolution of archosaurs: relationships and the origin of major clades. Bulletin of the American Museum of Natural History 353:1-292.

Perez Loinaze, V. S., E. I. Vera, L. E. Fiorelli, J. B. Desojo. 2018. Palaeobotany and palynology of coprolites from the Late Triassic Chañares Formation of Argentina: implications for vegetation provinces and the diet of dicynodonts. Palaeogeography, Palaeoclimatology, Palaeoecology 502: 31 - 51.

Rogers, R. R., A. B. Arcucci, F. Abdala, P. C. Sereno, C. A. Forster, C. L. May. 2001. Paleoenvironment and taphonomy of the Chañares Formation tetrapod assemblage (Middle Triassic), northwestern Argentina: spectacular preservation in volcanogenic concretions. Palaios 16: 461 - 481.

Romer, A. S. 1966. The Chañares (Argentina) Triassic reptile fauna. I. Introduction. Breviora 247: 1 - 14.

Romer, A. S. 1966. The Chañares (Argentina) Triassic reptile fauna. II. Sketch of the geology of the Rio-Chañares-Rio Gualo Region. Breviora 252: 1 - 20.

Romer, A. S. 1967. The Chañares (Argentina) Triassic reptile fauna. III. Two new gomphodonts, Massetognathus pascuali and M. teruggii. Breviora 264: 1 - 25.

Romer, A. S. 1968. The Chañares (Argentina) Triassic reptile fauna. IV. The dicynodont fauna. Breviora 295: 1 - 25.

Romer, A. S. 1969. The Chañares (Argentina) Triassic reptile fauna. V. A new chiniquodontid cynodont, Probelesodon lewisi - cynodont ancestry. Breviora 333: 1 - 24.

Romer, A. S. 1970. The Chañares (Argentina) Triassic reptile fauna. VI. A chiniquodont cynodont with an incipient squamosal-dentary jaw articulation. Breviora 344: 1 - 18.

Romer, A. S. 1971. The Chañares (Argentina) Triassic reptile fauna. VIII. A fragmentary skull of a large thecodont, Luperosuchus fractus. Breviora 373: 1 - 8.

Romer, A. S. 1971. The Chañares (Argentina) Triassic reptile fauna. IX: The Chanares Formation. Breviora 377: 1 - 8.

Romer, A. S. 1971. The Chañares (Argentina) Triassic reptile fauna. X. Two new but incompletely known long-limbed pseudosuchians. Breviora 378:1-10.

Romer, A. S. 1971. The Chañares (Argentina) Triassic reptile fauna. XI. Two new long-snouted thecodonts, Chanaresuchus and Gualosuchus. Breviora 379: 1 - 22.

Romer, A. S. 1972. The Chañares (Argentina) Triassic reptile fauna. XII. The post cranial skeleton of the thecodont Chanaresuchus. Breviora 385: 1 - 21.

Romer, A. S. 1972. The Chañares (Argentina) Triassic reptile fauna. XIII. A fragmentary skull of a large thecodont, Luperosuchus fractus. Breviora 389: 1 - 8.

Romer, A. S. 1972. The Chañares (Argentina) Triassic reptile fauna. Lewisuchus admixtus, gen. et sp. Nov., a further thecodont from the Chañares beds. Breviora 390: 1 - 13.

Romer, A. S. 1972. The Chañares (Argentina) Triassic reptile fauna. XV. Further remains of the thecodonts Lagerpeton and Lagosuchus. Breviora 394: 1 - 7.

Romer, A. S. 1972. The Chañares (Argentina) Triassic reptile fauna. XVI. Thecodont classification. Breviora 395:1-24.

Romer, A. S. 1972. The Chañares (Argentina) Triassic reptile fauna. XVII. The Chañares gomphodonts. Breviora 396: 1 - 9.

Romer, A. S. 1973. The Chañares (Argentina) Triassic reptile fauna. XVIII. Probelesodon minor, a new species of carnivorous cynodont; family Probainognathidae nov. Breviora 401: 1 - 4.

Romer, A. S., and A. D. Lewis. 1973. The Chañares (Argentina) Triassic reptile fauna. XIX. Postcranial materials of the cynodonts Probelesodon and Probainognathus. Breviora 407: 1 - 26.

Romer, A. S. 1973. The Chañares (Argentina) Triassic reptile fauna. XX. Summary. Breviora 413: 1 - 20.

Sereno, P. C., and A. B. Arcucci. 1994. Dinosaurian precursors from the Middle Triassic of Argentina: Marasuchus lilloensis, gen. nov. Journal of Vertebrate Paleontology 14(1):53-73.

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twarda · 6 years ago

Photo

Putting this here because of references & long text. These are WIP. I’ll post the full picture later (Edit: this one link)

I made a Staurikosaurus pricei artwork (paleoart?) because I couldn’t find any good art when I needed it. There are 2 versions of it: scaled and with a speculative integument. Cranium, manus and pes based on Herrerasaurus ischigualastensis. Due to being a rather small animal, with most probably a quite large head, I enlarged the eye opening slighty. Colours inspired by owls, lynx, bobcat and civets because I wanted some nice pattern, in case of forests.

References below, just in case.

Sereno, P. C., & Novas, F. E. (1994). The skull and neck of the basal theropod Herrerasaurus ischigualastensis. Journal of Vertebrate Paleontology, 13(4), 451-476.

Sereno, P. C. (1994). The pectoral girdle and forelimb of the basal theropod Herrerasaurus ischigualastensis. Journal of Vertebrate Paleontology, 13(4), 425-450.

Novas, F. E. (1994). New information on the systematics and postcranial skeleton of Herrerasaurus ischigualastensis (Theropoda: Herrerasauridae) from the Ischigualasto Formation (Upper Triassic) of Argentina. Journal of Vertebrate Paleontology, 13(4), 400-423.

Bittencourt, J. D. S., & Kellner, A. W. A. (2009). The anatomy and phylogenetic position of the Triassic dinosaur Staurikosaurus pricei Colbert, 1970. Zootaxa, 2079(1), e56.

Grillo, O. N., & Azevedo, S. A. (2011). Recovering missing data: estimating position and size of caudal vertebrae in Staurikosaurus pricei Colbert, 1970. Anais da Academia Brasileira de Ciências, 83(1), 61-72. Chicago

Thulborn, T. (2006). On the tracks of the earliest dinosaurs: implications for the hypothesis of dinosaurian monophyly. Alcheringa, 30(2), 273-311.

Scott Hartman’s Herrerasaurus skeleton: https://www.deviantart.com/scotthartman/art/Five-little-piggies-292594542

The Staurikosaurus skeleton featured on Wikipedia: https://en.wikipedia.org/wiki/Staurikosaurus#/media/File:Staurikosaurus_reconstruction.jpg

Saurischian muscle double-check based on RJ Palmer’s T. rex https://www.deviantart.com/arvalis/art/Tyrannosaurus-rex-2018-767137215

And http://www.paleofile.com/Dinosaurs/Theropods/Staurikosaurus.asp (used Google archived thumbnails, as the site was unfortunatelly unavailable when I was collecting references).

#dinosaur #staurikosaurus #herrerasaurus #paleoart #artists on tumblr #digitalart #digital #painting #process #wip

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almomentoqueretaro · 3 years ago

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Hallan nueva criatura que se extinguió hace miles de años

Se trata del Beornus honeyi, una criatura bautizada en homenaje a Beorn debido al aspecto de los molares como inflados. Esta especie es una de las tres nuevas criaturas antiguas de los albores de los mamíferos modernos que han sido descubiertas y descritas en una reciente investigación publicada en el Journal of Systematic Paleontology, en y que sugiere una rápida evolución inmediatamente…

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paleochick · 7 years ago

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THIS GIANT OTTER was described by my boss, Dr. Denise Su! #Repost @fossil_librarian ————————- It’s #WorldOtterDay!!! Do you think otters are totes ardorbs?? Well how about a 110lbs (50kg) otter with a crushing bite? In 2017, researchers published on a new giant otter they named “Siamogale melilutra”. The fossils were discovered in late Miocene (~6 mya) lignite beds of Shuitangba, Yunnan Province, China. This wolf-sized otter is larger than all living otters. The heaviest extant otter is the Sea Otter weighing in at 14-45kg. Researchers also compared the bite force of “S. melilutra” to ten other living otter species and found it had crushing teeth and robust jaws that were 6x sturdier than the extant otters. Possibly acquiring these traits to eat the abundance of big clams at this time. 1) cranium - image from Wang, X., Grohé, C., Su, D. F., White, S. C., Ji, X., Kelley, J., ... & Yang, X. (2018). A new otter of giant size, Siamogale melilutra sp. nov.(Lutrinae: Mustelidae: Carnivora), from the latest Miocene Shuitangba site in north-eastern Yunnan, south-western China, and a total-evidence phylogeny of lutrines. Journal of Systematic Palaeontology, 16(1), 39-65. 2) comparison of crania of Siamogale and Lutra (European Otter) - image from Tseng, Z. J., Su, D. F., Wang, X., White, S. C., & Ji, X. (2017). Feeding capability in the extinct giant Siamogale melilutra and comparative mandibular biomechanics of living Lutrinae. Scientific Reports, 7(1), 15225. ⚒ . . . #otter #giantotter #siamogale #china #yunnanprovince #cenozoic #miocene #biomechanics #paleontology #peerreview #publication #science #research #researchpaper

#otter #science #siamogale #giantotter #cenozoic #yunnanprovince #paleontology #miocene #peerreview #researchpaper #research #repost #publication #biomechanics #worldotterday #china

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typhlonectes · 2 years ago

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Scientists Discover Bug-Eating Reptile That Lived Among Dinosaurs

Delicate fossil reveals a cousin of the modern tuatara

The Morrison Formation is a fossil wonderland. Inside these layers of multi-colored sedimentary stone, the remains of Allosaurus, Stegosaurus, Apatosaurus and more have been found through more than a century of fossil hunting. But these Jurassic rocks contain far more than the bones of “terrible lizards” that lived large. Fossils of small creatures have been filling in what the world of the Morrison Formation was really like, including a new fossil reptile with ties to the modern tuatara.

Named Opisthiamimus gregori, the small creature was a bug-hunting reptile that lived in Wyoming roughly 150 million years ago. Despite the animal’s lizard-like appearance, however, it was not a lizard.

Instead, it belonged to a different group of reptiles known as rhynchocephalians. Described by Smithsonian National Museum of Natural History paleontologist Matthew Carrano and colleagues today in the Journal of Systematic Paleontology, Opisthiamimus was part of that group that flourished in the time of the dinosaurs but is only represented by the tuatara of New Zealand today...

Read more: https://www.smithsonianmag.com/science-nature/scientists-discover-bug-crunching-reptile-that-lived-among-dinosaurs-180980757/

#prehistoric #tuatara #rhynchocephalia #reptile #herpetology #science #nature #animals #north america

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biogenericpublishers · 4 years ago

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Comparative Osteometric Study of Some Selected Bones of Local Domestic Turkey and Guinea Fowl by Bello Abdulrahman in Open Access Journal of Biogeneric Science and Research

Abstract

The research was conducted in the Gross section of Veterinary Anatomy laboratory with the aim of preparation and comparing some skeleton bones of local domestic turkey and guinea fowl. Samples were purchased, sacrifice, feather and excess flesh were removed and boiled using water to produce the bones. The duration of process was recorded. Comparative biometry study was conducted on some selected bones (scapular, coracoid, furcular and tibiotarsus) and the bones were mounted using wooden stand, copper wire, and adhesive gum with the aim of enhancing avian teaching. Based on the processes of the research. It was recommended to use plastic materials in production of skeletal models to avoid deterioration of bones for proper teaching in veterinary anatomy.

Keywords: Local domestic turkey, Guinea fowl, Scapular, Coracoid, Furcular, Tibiotarsus

Introduction

Avian also known as birds are a group of endothermic vertebrates whose characteristics include feathers, toothless beaked jaws, laying of hard-shelled eggs, four chambered hearts and a strong but lightweight skeleton. Avian live all around the world and vary in size with the smallest being the bee hummingbird with a height of 2cm and the largest being the ostrich with a height of 2.75m. There are approximately ten thousand species (10,000) of birds around the whole world [1]. Chickens and turkeys are the most commonly reared avian because of their high economical and health importance to humans [1].

Osteology is the study of the structures and function of the skeleton and bony structures. It is the scientific study of bones it is a sub discipline of anatomy. Bones make up a skeleton; they are designed to provide adequate strength with minimal mass or weight. Based on development, we have Endochondral and Intramembranous bones. Based on location, are classified based on Axial and Appendicular skeleton, while based on shape, we have long bones short bones, flat bones, irregular bones and sesamoid bones.

The Skeleton is defined as the frame work that supports, protects and forecasts the body structure of an organism [2]. The skeleton can be classified into two based on their location as internal and external skeletons. Skeleton come in a number of forms, each suited for a particular set of lifestyles and environment. Skeletons can be rigid, semi-rigid or soft. vertebrates have internal skeleton called bony skeleton, which consist mainly of calcified bone tissues The internal skeletons are hard mineralized structures that are located within the muscles of the organisms. The internal skeletons provide protection, support and enable movement of the muscle. The external skeletons are hard encasements on the surface of organisms, insects and animals. Examples of external skeleton include shells of crabs and insects. This external skeleton provides defense against predators, allows for movement and supports the body [1].

The skeleton is composed of bones, cartilages and ligaments. Skeletons of animals and birds are the basic need of the veterinary study, especially for the veterinary gross anatomy [3]. These skeletons are necessary for research ranging from phylogenic investigations to age and growth analyses to functional morphology [4] and essential tools for the study of systematic, biomechanics, evolutionary morphology & adaptation, paleontology and identification of animal remains from archeological sites. It is the backbone of the study of many pathological conditions. It is the backbone of the study of many pathological conditions [4].

Turkey is an avian specie (Meleagris gallopavo) which is a large gallinaceous bird of the family Meleagridae, which is a native of North America. There is only one turkey breed but there are many turkey species. The popular varieties that have attained commercial importance in different parts of the world are the Broad Breasted, Large White and the Broad Breasted Bronze. Other breeds are the White Holland, the Beltsville Small White, the Black, the Bourbon Red and the Narrangansell [5]. Male turkeys have a distinctive fleshy wattle or protuberance that hangs from the top of the beak called a (snood). They are among the largest birds in their ranges. As in many Galliformes, the males are larger and much more colorful than females. Turkeys are classed in the family phasianidae in the taxonomic order of meleagris ocellata. The meleagris is the only extent genus in the subfamily meleagrididae, but now subsumed within the family phasianidae. The two main species are distributed thus: meleagris gallopavo also known as domestic turkey or wild turkey are found in forests of North America, Throughout the Midwest and in southern Canada meleagris ocellata also known as ocellated turkey are found in the forests of the Yucatan peninsula [6]. Turkeys are reared using a domesticated system in Europe, a semi domesticated system and free-range system in Africa. Turkeys have an estimated population of over seven million turkey’s worldwide [6].

Guinea fowls are the largest living bird reaching over 200 kg body weight and 2.7cm in height. It is classified under Ratites, which are large ground dwelling, flightless birds such as rhea, emu, cassowary, and kiwi. Guinea fowls also known as original fowl are birds of the family numididae in the order Galliformes. They are endemic to Africa and rank among the oldest of the gallinaceous birds. Phylogenetically, they branch off from the core Galliformes after the cracidae and before the odontophoridae, which is an Eocene fossil lineage, telecrex. [7]. The insect eating, ground nesting birds of this family resemble partridges, but with featherless heads, though both members of the genus guttera have a distinctive black crest, and the vulturine Guinea fowl has a downy brown patch on the nape. Most species of Guinea fowl have a dark grey or blackish plumage, with dense white spot, but both members of the genus angulates lack the spots.

Skeleton of animals and birds are the basic need of the veterinary study, especially for the veterinary gross anatomy [3]. These skeletons are necessary for research ranging from phylogenic investigations to age and growth analyses to functional morphology [4] and essential tools for the study of systematic, biomechanics, evolutionary morphology and adaptation, paleontology and identification of animal remains from archeological sites. It is the backbone of the study of many pathological conditions. It is the study of many pathological conditions [4]. This work is done to make available the morphometrical studies of the bones of an adult turkey and guinea fowl for analysis and comparative studies in the study of the skeletal anatomy of bones. The aim of the research is to compare Morphological and biometric parameters of some selected bones of clinical importance in an adult local domestic turkey and guinea fowl

Materials and Methodology Study Area

The city of Sokoto is located in the extreme North West of Nigeria near to the confluence of river Sokoto and River Rima. Sokoto has a land size of 25,973 km2 with population of 3,702,676 people. Sokoto state shares a boarder with Niger Republic, Zamfara state and Kebbi State.

The northwestern state was created in 1967, seven years after Nigeria got her independence from the Britain. It was later split into Sokoto and Niger and Sokoto was then split into Kebbi and Zamfara in 1991 and 1996 respectively. The state has an annual average temperature of 28.3, making it one of the hottest cities in the world, however the maximum daytime temperatures are generally under 40 °C most of the year although it could go above. Sokoto currently is the second largest producer of livestock in Nigeria. With an estimate of 1.18 million cattle, 2.90 million goats, 1.90 million sheep, 2.0 million chickens and turkeys, 45,000 camels, 34,532 horses and 51,388 donkeys.: Statistical Analysis of Scapula of Both Turkey and Guinea Fowl.

Sample Collection and Processing

Ten (10) fully grown and matured turkey of age 2-3 years and ten (10) fully-grown matured guinea fowl of age 2-3 years were selected based on their history, physical appearances and lack of any skeletal abnormalities. These breeds were all obtain from the local houses in Sokoto town. It was ensured that there were no congenital deformities and scars present in the samples. The avian were later processed for biometric comparative analysis in the gross Anatomy Laboratory of the Faculty of Veterinary Medicine at Usmanu Danfodiyo University Sokoto, Sokoto State.

The birds were then sacrificed by the severing of the jugular veins; great care was taken so as not to damage the bones of the neck. They were then de-feathered by emancipation in hot water and the feathers were then plucked out. The internal organs of the birds were gently removed after de-feathering had being done. The birds were then de-fleshed using a sharp scalpel blade, carefully removing the feathers from the thighs, the pectoral muscles and muscles from the wings. The remaining adhering muscles were removed by hot water and maceration technique. The turkey and guinea fowl were then boiled separately and a little of potash was added to help in the loosening of the flesh. The boiling lasted for45 minutes. After boiling, the flesh of the birds was removed gently using scalpels blades, forceps, knives and hands. The bones were then soaked in water for four days. Great care was taken so as to avoid damage to the bones from boiling.

The bones were then rinsed and washed with detergent and then dried in the open for 3 days. After drying the bones were then treated with bleaching reagents (hydrogen peroxide) so as to prevent them from decaying and to prevent insects from burrowing into them, the bones were soaked in water and hydrogen peroxide solution for four days and then kept out to dry for two days. A biometric study on a comparative study of the turkey and guinea fowl was then carried out by taking certain measurements of selected number of bones of the turkey and guinea fowl using meter rule, digital Vernier caliper, strong white thread, digital weighing balance. The results of this measurements are shown in (Tables 1-8). After taking the measurements the bones were then assembled and the skeleton was mounted.

Materials Used

After successful separation and processing of bones, the bones were measured and mounted afterwards using the following materials

Digital caliper

thread

Meter rule

Digital weighing bal.

Top bond

Four-min. adhesive glue

One-minute super glue

Saw dust

Scalpel blade

Thumb forceps

Copper wire

Ply wood

Wooden rod stand

Drilling machine

Screw nails.

The digital caliper is a precision instrument that can be used to measure internal and external distances extremely accurately, it is used by sliding the jaw along the main scale, the rectangular plates align and misaligns and the capacitance (the amount of electrical charge) between the plates changes. This sends a signal to a chip within the caliper, which generates the readings shown on the LCD display. Calipers usually give a precision to 0.01mm (10 micrometers), or one thousandth of an inch. It has a resolution of 0.1mm and accuracy of 0. 2mm.Digital weighing balance also known as beam balance was used to take the weights of the selected bones measured, it is a simple device. The bones were placed on the plate of the weighing balance and the readings were read from the LED display monitor.

Thread and meter rule were used simultaneously. The thread was used in measuring curved and rough areas of the bones and then placed on the meter rule to ascertain the measurement. The meter rule was used in straight bones and bones with few rough and less curved surfaces majorly to determine the length of such bones.

Biometric

This is the application of statistical data to biological data, it is the measurement and statistical analysis of unique physical and behavioral characteristics. In this study, it involves the statistical analysis between selected bones of an adult turkey and an adult guinea fowl, the use of standard error of mean also known as standard deviation and a software known as statistical analysis system to determine the difference and the accuracy of the measurements taken.

Bones Used

The bones used for the comparative study in this research work are the

Scapula

Coracoid

Furcular

Tibio tarsus

The selected bones were singled out and the various parameters used in the research were marked and used in the measurements carried out. The values gotten from bones of the turkey were compared to the value of bones gotten from that of the guinea fowl. Various instruments were used in the measurements depending on the nature of the bone measured and the expected result required from that parameter.

Landmark The anatomical landmarks used in the study were, for tibio tarsus

Tibio Tarsus

Weight of the tibiotarsus

Distance from the medial to the lateral condyle

Circumference of the mid shaft

Distance from the lateral cnemial crest to the medial cnemial crest

Length of the deep groove

Total length of the tibio tarsus

Circumference of the proximal 1/3 of the tibio tarsus

Circumference of the distal 1/3 of the tibio tarsus.

Scapula

Weight of the scapula

Total length of scapula

Length of the pneumatic foramen

Length from the scapular tubercle to the caudal part of the scapular

Length from the scapular tubercle to the cranial part of the scapular

Distance from the blade to the vertebral border

Circumference of the scapular neck

Distance from glenoid facet to acromion

Width of scapular neck

Coracoid

Weight of the coracoid

Length of the triosseal canal

Length of the deep pneumatic foramen

Distance from the lateral condyle to the medial condyle

Length of the sternal facet

Width of mid shaft

Distance from triosseal canal to deep pneumatic foramen (proximal part)

Total length of the coracoid

Furcula

weight of the furcular

distance between right and left clavicle

length of right clavicle

length of left clavicle

Statistics

Standard Error of Mean

The standard error is a statistical term that measures the accuracy with which a sample distribution represents a population by using standard deviation. In statistics, a sample mean deviates from the actual mean of a population this deviation is the standard error of the mean

SAS is a command-driven software package used for statistical analysis and data visualization.

Results and Discussion

Gross Observation

The results from the study of the morphometry and biometric of selected bones of both adult turkey and guinea fowl are reported below.

After gross comparison of the selected bones from the turkey and guinea fowl (tibiotarsus, coracoid, scapula, and the furcular) the following observations were made and differences noticed concerning the furcular;

The furcular of turkeys was found to be clearly triangular in shape and both clavicles are flattened with an inverted groove at the medial side. The inter clavicle is pointed ventrally (Figures 1-5). The furcular of guinea fowls is slightly triangular in shape but both clavicles are curved in a convex manner cranially. The edges at the proximal part tapers and the inter-clavicle are bilaterally flattened.

Biometric Study

Discussion

The study revealed that most studies carried out that involve preparation and mounting of skeleton of avian species used water and heat maceration and use of chemicals such as sodium perforate. The preparation involves skinning, removal of the skin completely, removal of viscera and other soft organs before removal of muscles close to their attachment and insertion into the bones and cartilages, disarticulation and cleaning using water and a pair of forceps. Bleaching and curing to preserve the bones using either chlorine solution, hydrogen peroxide or lime water.The most fully documented historical account of skeleton production is that of the Smithsonian institute, with his formula of 72-hour hot water soaking, brushing, and the use of benzene, which has proven to be highly toxic.

The assemblage of avian skeleton involves consulting a diagram of the said avian anatomy as done in this study to ensure proper assemblage of the skeleton. Snyder, Burdi, and Gaul introduced a method of skeletal preparation that involved a quick acting formula they named anti- forming, prepared by combining sodium carbonate and bleaching powder. The authors note that other effective means are time consuming. They state that the five-step method of maceration, cleaning, degreasing, bleaching, and fixing as well as the use of domestic beetles are, in effect, not necessary. Synder notes that hydrogen peroxide and potassium hydroxide are especially useful for bones that may crack or degrade from repeated boiling and scraping, such as skull and scapula. Another method discussed that may help to avoid decalcification is macerating uncovered in clear water for a few days to weeks, followed by immersion in a detergent solution and simmered. [8].

Detergent maceration makes use of the enzymes present in the cleaning agent, and an increased speed of maceration and removal of bad smell have been observed. However, key here is that the exact composition of commercial detergents is often proprietary and not directly available. Besides various kinds of enzymes, the detergents also contain ten sides, builders (inorganic complexing agents), additives, bleaching agents and corrosion inhibitors. The aggressive mixture in detergents may cause damage to specimens and decalcification, softening and transparency of detergent-macerated bones. [9].

Yin warned of the adverse effects of enzymatic maceration on hardness of bones, and a year later [9 -20] applied various concentrations of lipase and protease, with successful results reported. Having said that, the materials and methods of four works reviewed associate in a similar mindset as each experiment builds on those whose research came before. Each scientist modifies previous works. Reducing bone modifications as well as increasing potential genetic material have become primary goals. While summary reviews are enumerated, the one point that all agree on is the negative effect of bleaching with sodium hypochlorite. All caution against its use, warning that resultant bone will be flanky and at times crumble quickly to dust. They instead suggest hydrogen peroxide or potassium hydroxide, which was used during this study [21-32].

Conclusion

The study revealed that the measured parameters have been individually evaluated for both left and right sides of the turkey and guinea fowl using two replications per treatment. The data were analyzed using Duncan system grouping and mixed procedure of statistical analysis system. The significant differences between means were detected using Duncan’s multiple range tests [23-41]. The standard error of mean is set at P< 0.05. Mounting of avian skeleton is possible but requires the use of an aged (old) bird for the betterment of necessary anatomical features. Comparative anatomical features such as foramina, crest, depressions, pneumatization, and ridges might be seen in some species and not seen in others. The most recommended flesh removal method is the maceration technique and the use of hydrogen peroxide and potassium hydroxide instead of sodium hypochlorite which is known to weaken the bone and make it flanky.

Recommendation

The following recommendations were made for future research purposes. The need to use plastic models in the production of skeletal elements in enhancing veterinary anatomical teachings. Comparative analysis should be done on different flesh removal techniques in order to know which is more efficient and the use of different chemicals to ensure the specimen remain intact. Comparative analysis between breeds of local turkey, local chicken and guinea fowl should be done to see if there are differences in the anatomical features. Comparative analysis should be done on both sexes of the turkey breed of a given age. The use of other measuring and biometrical equipment’s should be used when carrying out further research.

More information regarding this Article visit: OAJBGSR

https://biogenericpublishers.com/pdf/JBGSR.MS.ID.00182.pdf https://biogenericpublishers.com/jbgsr-ms-id-00182-text/

#Local domestic turkey #Guinea fowl #Scapular #Coracoid #Furcular #Tibiotarsus #Bello Abdulrahman #oajbgsr #jbgsr #biogeneric publishers

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evoldir · 6 years ago

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Other: Peer Community in Evolutionary Biology

Dear colleagues We invite you to submit your preprints to Peer Community in Evolutionary Biology (PCI Evol Biol, https://evolbiol.peercommunityin.org) in order to obtain a recommendation from this community after peer-reviewing. **Some numbers:** -We're now more than 400 editors at PCI Evol biol -We've received 107 submissions of preprints. We've recommended 46 and are still evaluating 24 of them. -Mean time to 1st decision: 49 days PCI Evol Biol is a group of scientists who review and recommend preprints in evolutionary biology, free of charge and transparently. It is a research community working for researchers to create a new publication system that is completely free of charge and independent of private publishers. This community already includes 400 researchers (the full list can be found at https://evolbiol.peercommunityin.org/public/recommenders) motivated to review and recommend preprints. **Some important points:** -PCI Evol Biol is free for all users (readers AND authors); -PCI Evol Biol is supported by scientific societies including the Society for the Study of Evolution, the Society of Systematic Biologist, the Nordic Society Oikos, the French Ecology and Evolution Society (the SFE2), etc. (https://peercommunityin.org/who-supports-peer-community-in/); -PCI Evol Biol does not publish the preprints (they stay on the preprint server) but the associated reviews and recommendations; -PCI Evol Biol does not evaluate preprints already submitted for publication in a journal, in order to avoid parallel reviewings; -Authors can submit their preprints to traditional journals once they have been recommended by PCI Evol Biol. Reviews obtained before the recommendation can help improve the quality of the preprint; -Journals such as JEB, Evolution, Ecology Letters, Plos Biol, TREE, Evolutionary Applications, etc. (https://peercommunityin.org/pci-friendly-journals/) indicated that they will consider the preprints recommended by PCI Evol Biol and that they will take into account the reviews and recommendations of PCI Evol Biol in their own editorial process if adequate. -PCI Evol Biol's recommendations are transparent (reviews and recommendations are published, recommendations are signed, reviewers can remain anonymous if they wish); -Only reviews leading to a recommendation are published; -A preprint recommended by PCI Evol Biol is scientifically validated and can therefore be cited; -PCI Evol Biol's recommendations have a DOI, are referenced and can therefore also be cited; -Four other communities (PCI Ecology, PCI Paleontology, PCI Animal Science, PCI Entomology) also exist. -Anonymous submissions are possible To submit your preprints, simply go to https://evolbiol.peercommunityin.org click the 'Submit a preprint' button and follow the instructions. We hope to have aroused your interest, The Managing Board of PCI Evol Biol https://evolbiol.peercommunityin.org [email protected] https://youtu.be/4PZhpnc8wwo Thomas Guillemaud

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wtf-triassic · 5 years ago

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Foreyia maxkuhni

Etymology: Forey’s Fish

First Described By: Cavin et al., 2017

Time and Place: Foreyia lived about 240.91 million years ago, in the Ladinian of the Middle Triassic

Foreyia is known from the Prosanto Formation of Switzerland

Physical Description: Foreyia was a Coelacanth, a sort of Lobe-Finned Fish once thought to be a unique feature of prehistoric ecologies, and now known to survive in two different species today. This is wild, of course, but Coelacanths were weird in many different ways throughout their prehistoric tenure. Foreyia looked only a little similar to its cousins - it had a huge head compared to other Coelacanths, as well as a beak - something that you really only see in ray-finned fish and tetrapods - an underbite, and a horn on its head. That said, its body looks similar enough to other coelacanths, with dorsal fins and a wide tail fin, and large forelimb fins. However, the large size of its head makes it look like a Coelacanth that had been squished extensively, with the body looking quite short and squished compared to its close relative Ticinepomis. We aren’t sure as to what colors it may have been, but since it lived in a tropical region and may have had a similar niche as a Parrotfish, it is reasonable to suppose it may have been colorful. It was also very small, only around 20 centimeters long.

Diet: Given the beak, it’s likely that Foreyia ate hard food, potentially even similarly to living parrotfish - by chipping off algae covered rocks and reef builders, or potentially eating small shelled animals in the tidal pools.

Behavior: Foreyia’s head was huge, and so that likely impacted its swimming style, though it is unclear how. Modern Coelacanths moving very slowly through the water, moving their fins to help propel through. Since Foreyia reduced the size of its fins to an extent, it’s possible that the tail (which was very large compared to the rest of the body) was more vital in swimming, and the head may have been used to help steer (though this is just a hypothesis). The bony shield may have also been helpful in protecting Foreyia from danger, which makes sense ans many predators were present in its environment. This is at least somewhat supported by its strong clavicle muscles. It probably would have spent a significant amount of time grazing, either on small crunchy invertebrates or algae. Today, Coelacanths don’t seem to shoal much; however, that may not have been the case in the past, so we can’t infer a loner lifestyle for Foreyia.

Ecosystem: Foreyia lived in a coastal shelf environment, specifically in a tidal basin that would often become anoxic as the tide went out during the day, meaning that Foreyia had to move around a lot to avoid suffocation. This environment was probably at least somewhat reef or tidal pool like, with a variety of fish swimming around in the ecosystem. There were many ray-finned fish here, including Peltopleurus, Habrichthys, Archaeosemionotus, Saurichthys, Ctenognathichthys, Besania, Prosanticthys, Eoeugnathus, and Ducanicthys. There was also another Coelacanth, Ticinepornis. As for tetrapods, there was the Pachypleurosaur Neusticosaurus, the Helveticosaurid Eusaurosphargis, and the Tanystropheid Macrocnemus. These reptiles would have been major predators of Foreyia.

Other: Foreyia is so weird in its shape that the original authors proposed it was Heterochronic - ie, different aspects of baby Coelacanth anatomy were retained in order to provide useful adaptations for Foreyia. However, some later researchers have cast doubts on this idea, given that baby Coelacanths don’t… actually seem to resemble Foreyia. Clearly, the jury is still out!

~ By Meig Dickson

Sources Under the Cut

Arratia, G., and A. Herzog. 2007. A New Halecomorph Fish from the Middle Triassic of Switzerland and its Systematic Implications. Journal of Vertebrate Paleontology 27(4):838-849.

Bürgin, T., U. Eichenberger, H. Furrer and K. Tschanz. 1991. Die Prosanto Formation - eine fischreiche Fossil-Lagerstätte in der Mitteltrias der Silvretta-Decke (Kanton Graubünden, Schweiz). Eclogae Geologicae Helvetiae 84:921-990.

Bürgin, T., and A. Herzog. 2002. Die Gattung Ctenognathichthys (Actinopterygii, Perleidformes) aus der Prosanto-Formation (Ladin, Mitteltrias) Graubündens (Schweiz), mit der Beschreibung einer neuen Art, C. hattichi sp. nov. Eclogae Geologicae Helvetiae 95:461-469.

Carroll, R. L., and P. Gaskill. 1985. The nothosaur Pachypleurosaurus and the origin of plesiosaurs. Philosophical Transactions of the Royal Society B 309:343-393.

Cavin, L., H. Furrer, and C. Obrist. 2013. New coelacanth material from the Middle Triassic of eastern Switzerland, and comments on the taxic diversity of actinistans. Swiss Journal of Geosciences 106:161-177.

Cavin, L., B. Mennecart, C. Obrist, L. Costeur, and H. Furrer. 2017. Heterochronic evolution explains novel body shape in a Triassic coelacanth from Switzerland. Scientific Reports 7(13695):1-7.

Ferrante, C., L. Cavin, H. Furrer, R. Martini. 2018. Coelacanths from the Middle Triassic of Switzerland show unusual morphology. Swiss Geoscience Meeting.

Fraser, N., and H. Furrer. 2013. A new species of Macrocnemus from the Middle Triassic of the eastern Swiss Alps. Swiss Journal of Geoscience 106:199-206.

Herzog, A. 2001. Peltoperleidus obristi sp. nov., ein neuer, kleiner Strahlenflosser (Actinopterygii, Perleidiformes) aus der Prosanto-Formation (Mitteltrias) von Graubünden (Schweiz). Eclogae Geologicae Helvetiae 94:495-507.

Herzog, A. 2003. Eine Neubeschreibung der Gattung Eoeugnathus Brough, 1939 (Actinopterygii; Halecomorphi) aus der alpinen Mitteltrais Graubündes (Schweiz). Palaeontologische Zeitschrift 77(1):223-240.

Herzog, A., and T. Bürgin. 2005. A new species of the genus Besania Brough 1939 from the Middle Triassic of Canton Grisons (Switzerland) with a discussion of the phylogenetic status of the taxon. Eclogae Geologicae Helvetiae 98:113-122.

McMenamin, M.A. S. 2018. Coelacanth Vestiges. Deep Time Analysis, Springer Publishing.

Scheyer, T. M., J. M. Neenan, T. Bodogan, H. Furrer, C. Obrist and M. Plamodon. 2017. A new, exceptionally preserved juvenile specimen of Eusaurosphargis dalsassoi (Diapsida) and implications for Mesozoic marine diapsid phylogeny. Scientific Reports 7:4406.

#foreyia #foreyia maxkuhni #coelacanth #Triass March Madness #triassic madness #triassic #prehistoric life #paleontology

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a-dinosaur-a-day · 5 years ago

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Silesaurus opolensis

By José Carlos Cortés

Etymology: Silesian Reptile

First Described By: Dzik, 2003

Classification: Dinosauromorpha, Dinosauriformes, Dracohors, Silesauridae, Sulcimentisauria

Time and Place: Around 230 million years ago, in the Carnian of the Late Triassic

Silesaurus is known from the Drawno Beds Formation of Poland

Physical Description: Silesaurus was a very common almost-dinosaur - specifically, the titular member of the Silesaurids - from Poland in the middle of the Triassic period. It was a quadrupedal animal, about 2.3 meters long and small enough that it most likely would have been covered in fluff. Like other Silesaurids, it was long - with a long neck and a long tail, and long limbs easily reaching to the ground. Like other Silesaurids, it almost had its legs directly underneath its body - it didn’t seem to have an open acetabulum, but rather a partially open one, though Silesaurids are something of a confusing case on this regard. It had a small head, with a little beak in the front, and small sharp conical teeth. In addition, it had very large eyes, giving it distinctly good eyesight, as well as a decent sense of smell. As a quadruped, its front limbs were rather extended, while the hind limbs did a lot of the weight support.

Diet: Interestingly enough, though for a long time it was thought that Silesaurus was an herbivore, recent fossil poop studies have indicated it was an insectivore - similar to living birds.

By Ripley Cook

Behavior: If Silesaurus really was an insectivore, it would have spent much of its time moving around in its environment, examining it closely for insects and pecking at the ground with its small beak for food. This pecking may have even looked a lot like that of living birds - the large eyes probably would have prevented the eyes from moving much, like in living birds, and as such Silesaurus would have had to bob its head in order to see. It would have been very careful in its environment, making sure to look for food and avoid predatory dangers in its environment. It would probably have been social - corroborated by the fact that it was very common in its environment - and taken care of its young to some extent. As an Archosaur, it would have been warm blooded as well, and very active.

Ecosystem: Silesaurus lived in a Mediterranean-esque scrub environment, with summer monsoon seasons and dry winters. The swampy coniferous forest and fernlands it lived in had a wide variety of animals, placing Silesaurus in a unique ecosystem of the Carnian age. This is actually quite important, given that the Carnian Pluvial Event - a minor mass extinction that helped to spur Dinosaurian evolution - occurred around the same time, leading to Silesaurus and its contemporaries being a snapshot of this change. A variety of invertebrates lived alongside this animal, giving it plenty of food, as well as Temnospondyls such as Metoposaurus and Cyclotosaurus, the Aetosaur Stagonolepis, the Phytosaur Parasuchus, the Rauisuchid Polonosuchus, the Sharovpterygid Ozimek, and probably some Tuataras and maybe even a Pterosaur. A small community, but a beautiful portrait of this time period, with its fair share of weirdos and precursors. And Silesaurus would have had a lot to look out for with Polonosuchus at just the right size to attack it.

Other: Do not let Silesaurus’s weird similarities to birds fool you - it wasn’t an early bird, but a showcase of how bird-like traits kept popping up over and over again in the line of animals leading up to them. In fact, the evolution of such a specialized feeding system is notable in such an early member of the Ornithodirans. Silesaurids in general are extremely interesting because of their mixture of characters - similar to dinosaurs, but not quite there; with legs almost directly underneath the body, but other traits that match the later Ornithischians. The problem with Ornithischians - the bird-hipped dinosaurs - is that they have a bit of a ghost lineage, aka even though they should have showed up at the same time as Theropods and Sauropodomorphs, they don’t until the Early Jurassic. This isn’t as big of a gap as some other examples, but it is notable. Silesaurids have come out as Ornithischians just enough times in phylogenetic studies to bring it up as a question - are they almost-dinosaurs? The first bird-hips (without having bird-hips)? Something else entirely? More research is necessarily, but one thing is for sure - this group of weird dinosaurian experiments is one to keep an eye on, especially as we learn more and more about them.

~ By Meig Dickson

Sources Under the Cut

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Nesbitt, S. J. 2011. The early evolution of archosaurs: relationships and the origin of major clades. Bulletin of the American Museum of Natural History 353:1-292.

Qvarnström, M., J. V. Wernström, R. Piechowski, M. Tałanda, P. E. Ahiberg, G. Niedźwiedzki. 2019. Beetle-bearing coprolites possibly reveal the diet of a Late Triassic dinosauriform. Royal Society Open Science 6 (3): 181042.

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