#tetanurae

[makairodonx]

Jurassic June 2024 Day 30: Allosaurus fragilis

[obscurefossils]

Siamraptor

Siamraptor was a genus of carcharodontosaurian dinosaur from the Early Cretaceous period. Its type species is S. suwati. The holotype was found in the Khok Kruat Formation in northeastern Thailand. Siamraptor is the first and currently only definite carcharodontosaurian known from Southeast Asia.

"Siam" is derived from the original name of Thailand, "raptor" is Latin for robber, and the specific name suwati refers to Suwat Liptapanlop, a supporter of the Northeastern Research Institute of Petrified Wood and Mineral Resources.

Its autapomorphies include a jugal with a straight ventral margin and a deep anterior process below the orbit, a surangular with a concavity and four posterior foramina, a groove along the suture between the surangular and prearticular, an articular with a formen at the suture with the prearticular, a cervical vertebra with an additional foramen that is excavating the parapophysis, and the presence of a pair of foramina at the base of the neural spine on the cervical and posterior dorsal vertebrae. Another possible autapomorphy specific to the genus may be a deep concavity excavating the posterior end of the lateral shelf.

Siamraptor is known from its holotype, consisting of a posterior right mandible including the surangular, prearticular, and articular; as well as referred material from three other individuals including three right premaxillae, a right and left maxillae, a left jugal, two posterior parts of the left mandible, three cervical vertebrae, a caudal vertebra, a manual ungual, a right ischium, a section of the left tibia, and a left pedal phalanx. Siamraptor was recovered as a definite carcharodontosaurian, though its relationships within the clade are uncertain. It may have been a derived member of Allosauria outside of Allosauridae or a basal member of Carcharosauria in a polytomy with Eocarcharia, Concavenator, and Neovenator.

Original paper: Original description paper

Wikipedia article: here

[kararadaygum]

..

[a-dinosaur-a-day]

Birds are class Aves.

Sure, under Linnaean taxonomy. But, well,

A) Linnaeus was a eugenecist so his scientific opinions are suspect and his morality is awful

B) he didn't know about evolution

C) he didn't know about prehistoric life

so his classification system? Sucks ass. It doesn't work anymore. It no longer reflects the diversity of life.

Instead, scientists - almost across the board, now - use Clades, or evolutionary relationships. No rankings, no hierarchies, just clades. It allows us to properly place prehistoric life, it removes our reliance on traits (which are almost always arbitrary) in classifying organisms, and allows us to communicate the history of life just by talking about their relationships.

So, for your own edification, here's the full classification of birds as we currently know it, from biggest to smallest:

Biota/Earth-Based Life

Archaeans

Proteoarchaeota

Asgardians (Eukaryomorphans)

Eukaryota (note: Proteobacteria were added to an asgardian Eukaryote to form mitochondria)

Amorphea

Obazoa

Opisthokonts

Holozoa

Filozoa

Choanozoa

Metazoa (Animals)

ParaHoxozoa (Hox genes show up)

Planulozoa

Bilateria (all bilateran animals)

Nephrozoa

Deuterostomia (Deuterostomes)

Chordata (Chordates)

Olfactores

Vertebrata (Vertebrates)

Gnathostomata (Jawed Vertebrates)

Eugnathostomata

Osteichthyes (Bony Vertebrates)

Sarcopterygii (Lobe-Finned Fish)

Rhipidistia

Tetrapodomorpha

Eotetrapodiformes

Elpistostegalia

Stegocephalia

Tetrapoda (Tetrapods)

Reptiliomorpha

Amniota (animals that lay amniotic eggs, or evolved from ones that did)

Sauropsida/Reptilia (reptiles sensu lato)

Eureptilia

Diapsida

Neodiapsida

Sauria (reptiles sensu stricto)

Archelosauria

Archosauromorpha

Crocopoda

Archosauriformes

Eucrocopoda

Crurotarsi

Archosauria

Avemetatarsalia (Bird-line Archosaurs, birds sensu lato)

Ornithodira (Appearance of feathers, warm bloodedness)

Dinosauromorpha

Dinosauriformes

Dracohors

Dinosauria (fully upright posture; All Dinosaurs)

Saurischia (bird like bones & lungs)

Eusaurischia

Theropoda (permanently bipedal group)

Neotheropoda

Averostra

Tetanurae

Orionides

Avetheropoda

Coelurosauria

Tyrannoraptora

Maniraptoromorpha

Neocoelurosauria

Maniraptoriformes (feathered wings on arms)

Maniraptora

Pennaraptora

Paraves (fully sized winges, probable flighted ancestor)

Avialae

Avebrevicauda

Pygostylia (bird tails)

Ornithothoraces

Euornithes (wing configuration like modern birds)

Ornithuromorpha

Ornithurae

Neornithes (modern birds, with fully modern bird beaks)

idk if this was a gotcha, trying to be helpful, or genuine confusion, but here you go.

all of this, ftr, is on wikipedia, and you could have looked it up yourself.

[paleonativeart]

Day 4: Chilesaurus

Ether supposedly to be a Tetanurae theropod or a basal Ornithischia, or even as both as a basal dinosaur, there is a bit unknown.

[captainswaglord500]

Cockatrice (Artwork by Yuujinner)

Kingdom: Animalia

Phylum: Chordata

Class/Clade: Reptilia (Sauropsida)

Clade: Diapsida

Clade: Archosauria

Clade: Dinosauria

Clade: Saurischia

Clade: Eusaurischia

Clade: Theropoda

Clade: Neotheropoda

Clade: Averostra

Clade: Tetanurae

Clade: Avetheropoda

Clade: Coelurosaria

Clade: Maniraptoriformes

Clade: Maniraptora

Clade: Pennaraptora

Clade: Oviraptorosauria

Clade: Edentoraptora

Superfamily: Caenagnathoidea

Family: Caenagnathidae?

Subfamily: incertae sedis

Genus: Ornithosaurus

Species: O. necrophilus (“death-loving bird lizard”)

Ancestral species: possibly Microvenator celer

Temporal range: late Pleistocene to recent (87,000 kya - present)

Information:

A ravenous scavenger, the cockatrice is by no means at the top of its food chain, though its uniquely offensive, musky odor, ear-splitting vocalizations, and proclivity for traveling in large groups called flocks make it a creature which few predators wish to tolerate. Add onto this its territorial aggression, and you have what may be Archaeonesia’s most detested scavenger. Cockatrices use their superb sense of smell to detect carrion from several tens of miles away, primarily feeding on the carcasses of various reptilian and mammalian megafauna, sometimes flocking around fresh kills made by larger predators and using their sheer number to overwhelm the carnivore into relinquishing its kill. Though it usually eats carrion, it is also classified as an opportunistic feeder, readily going after small vertebrates. Found primarily in the Arava Desert and the surrounding grasslands in the western half of the Isle of Perils, this medium-sized oviraptorosaur is known all throughout the Isle of Perils, including its central mountain range, making it one of the few non-avian dinosaurs to live in that region. It is also one of the few non-avian dinosaurs to actively seek out human settlements, particularly to feed on discarded scraps of food. Actively seeking out human settlements, it is known to scavenge from trash heaps and refuse bins, which make it a local pest in some areas. Entire flocks of these animals, as many as 40 individuals sometimes, may swarm landfills. Similarly, these creatures will use their sheer number of overwhelm larger carnivores into relinquishing kills before greedily tearing into their spoils. A pecking order can be observed amongst these animals, typically in which the largest male gets first pickings on the corpse. When feeding on carrion, as gruesome as it may be, they will typically eat away at the orifices first before hollowing out the cadaver. Due to its exceptionally strong stomach acids being able to kill most bacteria, it can eat carrion which most other scavengers would otherwise find too putrid or dangerous to consume. Attracted to shiny objects for the purposes of adorning their nests with them, they have been known to steal jewelry, though those which live farther from human settlements may instead use quartz and other naturally occurring crystals to adorn their nests. These animals are exceptional jumpers, being able to clear fences nearly 12 feet all and jump nearly 25 feet in a single bound. Exceptionally territorial in nature, groups may mark trees and rocks with a pair of scent glands behind their ears, which produce the foul musky odor typically associated with the animal. As these animals are quite social, their ability to recognize patterns (and more specifically faint color patterns and facial differences) allow them to differentiate between one another with remarkable ease. They can also recognize human faces with exceptional accuracy. Grooming behavior is well-documented, and like primates, it plays an important role in establishing social relations. Primarily diurnal, these animals rely on scent and eyesight to find food, and typically, a few individuals will venture away from the nesting grounds at a given time to locate food before they’ll go back and alert the others of its location, utilizing what is sometimes described as an elaborate“dance”, consisting of many different vocalizations, as well as head and body movements, to communicate location, much in the same way honeybees do. As the many environments it lives in are teeming with predators, a few individuals will take shifts throughout the night to watch the nesting grounds while the others sleep. A pouch at the base of the neck, commonly called a crop, allows the animal to store food before digesting it, though it serves a dual function of allowing it to transport food back to the nest to feed its offspring.

Though a given flock of cockatrices may not necessarily consist of entirely closely related individuals, it is more common than not for a flock to consist of a set of parents or grandparents and several generations of offspring. During the beginning of the dry season, around early December, the males’ colors will become substantially more flashy and eye-catching, his wattle flushing a bright maroon and violet color and the undersides of his wings flushing a pink hue, and although related species are known to engage in mock fights as part of mating displays, this species instead relies on a less violent method of winning approval from the females they wish to court: designing the most colorful display. A male will create a nest and adorn it with the most colorful materials he can found, anything from flowers and fruits to rocks and crystals. However, this is only part of the courtship ritual. While a bright nest may earn some initial interest from female suitors, it is what he does next that determines his success: performing an elaborate dance, sometimes with a shiny rock clutched in his beak, he will angle his head up towards the sky, revealing his brightly-colored wattle and wings. High-stepping in a circle around her, his throat will undulate to make a deep, rattling bellow, beating his wings and jumping up and down to keep her attention. If she accepts, she will join him in this dance and copulation begins. Cockatrices mate for life, and in 1.5 months time, she will lay a clutch of 2-4 blue eggs in the nest, and for the 5 weeks it will take for them to hatch, she will not leave the nest, the male fetching her food and water via his crop. When the young are born, they are, in a rare exception amongst non-avian theropods, altricial, being born nearly featherless and unable to walk for the first few weeks of life. By a month old, they will be able to walk. By a year, they will have reached half their adult size, being large enough to join their parents in the search for food. By 2 years, they will reach adult size, and at around 3.5 years, they will have gained their adult plumage and will reach sexual maturity. Many may choose to stay with their parents’ flock, though some may go off and form flocks with other young cockatrices. If they’re lucky, a cockatrice may expect to live 20-30 years.

Around the size of a cassowary, this species is around 5.6 feet tall, roughly 9-10 feet in length, and weighs around 200 lbs on the heavier side. There is no notable sexual dimorphism between species. The naked head is highly fluorescent, the neck being reddish yellow and the wattle/fleshy growths on its face being yellowish-orange and bluish-purple. The beak is red and the eyes are white. Plumage is white on the body and most of the wings, though near the base of the neck, the tail, and the wing feathers, the plumage starts to turn black, with the wing plumage having many beige spots along their length. Its legs are yellowish-gray.

Long-renowned for its dissonant calls, this species generally communicates with others of its kind with rasps, shrill humming, and a sound variously called “bleating” or “bugling”. Territorial calls consist of loud, deep booms which rumble across the land. However, it may hiss or honk if aggravated or in an attempt to intimidate and size up other scavengers/carnivores, and it has a characteristic shrieking whoop referred to by some as a “dinner bell call” to other cockatrices that food has been located.

Much in the same way that vultures are viewed as unclean and malevolent animals in Western society, so, too, is the cockatrice in Xenogaean society, made dually ironic for the fact that vultures also exist in the region, albeit typically in more montane environments. Long seen as a bad luck omen, stumbling across a dead cockatrice was said to signal impending disaster, particularly famine or drought, and in fact, it was said that if one did stumble across one, or managed to kill one, they were to immediately cremate it and spread its ashes in a river. Nonetheless, it does appear in some heraldic imagery and was venerated amongst some indigenous peoples in the region, particularly to the southeast. It was said the Bronze Age Aravan King, Kuntapurexa, infamous for his brutal conquests across the Isle of Perils, was followed by a horde of cockatrices which reaped the benefits of his conquests, feeding on the corpses of those he and his men killed as they went from village to village pillaging and marauding. The deafening sounds of these animals from afar was therefore used by some villagers as a way to determine how close Kuntapurexa and his men were to their settlement and therefore whether or not to abandon the town. How true this was, however, remains up to speculation, as no surviving historical records seem to confirm if this was a true account or not, with the possibility of it being a tall tale being rather likely. That said, if one can get past the animal’s revolting smell and dietary habits, a tame cockatrice makes for an exceptional companion animal, being exceptional at navigating, tracking, and retrieving items and trinkets, and in times past, some would use these animals to discretely transmit messages across long distances in a similar manner to messenger pigeons. On top of that, its affectionate nature towards those it’s acquainted with makes it decent as a pet as well, minus its food requirements. In fact, while some cities actively try to exterminate or otherwise relocate cockatrices within their walls, others may actively promote breeding programs for the animals in an effort to reduce waste in landfills. Despite being classified as a caenagnathid oviraptorosaurian, this placement is tentative: though its skull anatomy and genetic data would seem to support an inclusion amongst the Caenagnathidae or at least closer to the Caenagnathidae than the Oviraptoridae, the anatomy of its arms (and its wrists in particular) is exceptionally basal, more akin to that of therizinosaurs or ornithomimosaurs than to that of other oviraptorosaurs. Amongst an indigenous group in the Arava Desert region known as the Nge'echets, the cockatrice was seen as an embodiment of the desert itself, almost a god in its own right, far contrary to how their Xenogaean-speaking neighbors viewed the animal. As such, offerings were left out to the animals as a way of asking for safe passage from one oasis to the next as part of their migratory lifestyle. Nonetheless, amongst all native cultures in the region, the consumption of this animal’s meat is considered taboo due to its scavenging lifestyle. In lieu with its scavenging lifestyle, flocks of these animals may follow sick or injured animals for miles, waiting for them to collapse before finishing them off, hence it was long said that spotting a cockatrice behind oneself was a sign that death was on one’s doorstep. In some regions, they are also associated with the Xenogaean death goddess, Yerakiya, seen as either her messengers or even as a form she herself takes in the world of the living. Bones of this animal date back to the late Pleistocene, around 87,000 years ago, and fossil member of the genus are known as far back as the Miocene. A smaller closely-related species found on an offshore island, the basilisk (O. insularis), went extinct in the 18th century due to the introduction of pigs by British colonists. With around 2,000,000 mature adults in the wild, populations appear to be stable but declining in certain areas. 

[corbinscrawdadz]

Birds are def dinosaur descended, and as such dinosaurs within the group known as Paraves. Consider birds not dinosaurs, and you leave out a whole lot of dinosaurs such as

-almost bird

-almost but not bird

-looks bird… isn’t

-thought was bird? No! Think again!

-old bird…

Etc etc.

Basically the cladistics for BERD goes… hold on Lemme look it up…

-Dinosauria (all dinosaurs)

-Saurischia (lizard hipped dinosaurs. Which is weird. Because the birds are technically lizard hipped instead of bird hipped.)

-Theropoda (Three toed dinosaurs)

-Averostra (no fifth metacarpal ig?)

-Tetanurae (fellas with the stiff tails)

-Coelurosauria (all theropods more closely related to birds than Giganotosaurus n pals)

-Tyrannoraptorans (interesting one here- all dinosaurs descended from the common ancestor of a tyrannosaurus and a sparrow)

-Maniraptora (birds and dinosaurs more closely related to birds than ornithomimus. These are the ones where, if they were alive today, they’d probably just be called ‘weird birds’ or something)

-Paraves (this is like almost-almost birds. If they were alive today though, they’d probably be called birds. I mean, look at em! Look up super accurate paleo art of any dromeaosaur and you could definitely see that if any were still alive, some medieval knight would go like ‘ah yes! The majestic and horrific Ground Hawk! This is a bird. but with teeth’)

-Avialae (lots of ‘almost but not bird’ here)

-Pygostylia (honestly I think we might just be able to call most of those birds at this point.)

Go through two more levels of classification, anddd…

-Aves (bird)

… while, yes, I literally just clicked links on those cladistics tables in wikipedia, and I left out a few levels because I didn’t want to go on for too long, this should hopefully show how the birds are our last dinosaurs. Just, this time, able to steal your fries and fly away without you able to do anything about it.

Sure, they’re not going to swallow you whole or break every single bone like their old relative the rex, but you’re not getting that fry back.

Ever.

CLADISTICS ruined my life

[cacatoto-2024]

Cryolophosaurus (/ˌkraɪoʊˌloʊfoʊˈsɔːrəs/ or /kraɪˌɒloʊfoʊˈsɔːrəs/; "CRY-oh-loaf-oh-SAWR-us") adalah sebuah genus dari Theropoda besar yang diketahui hanya dari satu spesies tunggal, Cryolophosaurus ellioti, diketahui dari periode Jura Awal di Antarktika. Panjangnya sekitar 65 meter (213,3 ft) dan beratnya sekitar 465 kilogram (1.025 pon), menjadikannya salah satu theropoda terbesar pada masanya. Individu dari spesies ini bahkan mungkin telah tumbuh lebih besar, karena satu-satunya spesimen yang diketahui mungkin merupakan theropoda yang belum dewasa sepenuhnya. Cryolophosaurus diketahui dari satu tengkorak, satu tulang paha, dan material lainnya, tengkorak dan tulang paha tersebut yang telah menyebabkan klasifikasinya menjadi sangat bervariasi. Tulang pahanya memiliki banyak karakteristik primitif yang mengklasifikasikan Cryolophosaurus sebagai dilophosaurid atau neotheropoda di luar Dilophosauridae dan Averostra, sedangkan karena tengkoraknya memiliki banyak ciri lanjutan, menyebabkan genusnya dikategorikan tetanuran, abelisaurid, ceratosaur, dan bahkan allosaurid. Sejak deskripsi awalnya, konsensusnya adalah bahwa Cryolophosaurus termasuk di antara anggota primitif dari Tetanurae atau kerabat dekat dari kelompok itu.

[procyonvulpecula]

Hi everyone, hope you’re all staying safe and staying indoors during this pandemic!

I had a go at drawing a Tyrannosaurus rex skeleton in Paint (I based it on lots of different drawings and photos of skeletons I saw, but the one I used the most is the Nation’s T. rex at the Smithsonian. The leg stance is my own, so palaeotumblr, let me know if that’s anatomically impossible!)

After that I decided to have a go at giving it a body. I hope I didn’t make it too shrink-wrapped?

Palaeoartists - feel free to give me a critique so I can improve for next time!

A few things I opted to include, along with sources linked:

Feathers on the back and arms, but nowhere else.

Lips. Enamel has been found preserved on theropod teeth, which needs to be kept wet. Crocodilians live in water so don’t need lips, but theropods may have.

Crocodile-like integument on the face.

Neck ribs and gastralea (stomach ribs), which are delicate, hard to mount and often missing from museum skeletons!

Keratinised facial features are from this Your Dinosaurs Are Wrong video.

I tried to make it obvious that the eyes face forward, the hands are supinated, not pronated, and the feet are digitigrade - common mistakes in beginner dino art!

Possible mistakes I can see already, palaeotumblr let me know!

The tail looks way too thin to be an effective counterweight to that huge head, should it be thicker?

More keratin on the lachrymal than just that little eyebrow-like ridge?

Would the feathers stop there, or would they plausibly extend all the way down the dorsal side of the tail? I know the ventral side was scaly as we have impressions for that. 

The teeth need to be more obviously heterodont, but that’s hard to draw in Paint!

[paleospec]

Monolophosaurus jiangi (Zhao & Currie 1993) Klad - Tetanurae

[tapwing]

:Tetanurae matriarch: 3-6 To confirm foreign development the team located and recalled one of our active Matriarchs to compare how the ‘caged’ and ‘wild’ specimens develop. The cage Matriarch grew only slightly and remained physically unchanged. The wild specimen however, grew substantially and adapted common traits of theropoda. Losing it’s wings and developing denser structure along with a more muscular build that serve it in grappling or climbing. Some unknown growths spark concern, but nothing outside of the current margin of error. Further observation required.

[killdeercheer]

It is a little known fact that the lives Mesozoic dinosaurs often depended on whether shaved apes 145 million years in the future care about you.

[rmyers08]

Day 13: #drawdinovember2017 #megalosaurus I just realized I may never have drawn this species before despite the historical importance. Among the first #dinosaurs named and identified. In a world of feathered, ornamented, swimming, flying, bat-winged and weird dinos it’s passed over as a bit of a plain-Jane #theropod ... #drawdinovember #tetanurae #megalosaur

[alphynix]

Mirischia asymmetrica, a theropod dinosaur from the Early Cretaceous of Brazil (~112-99 mya). Although known only from its hips and a few other partial bones, these pieces were so well-preserved that it was given a genus name that translates to “wonderful pelvis”.

In life it would have been about 2m long (6′6″), but since the known fossil represents a subadult its full-grown size may have been a little bit larger. It was probably a member of the compsognathids, closely related to Compsognathus and Aristosuchus -- which would make it the only representative of that family currently known from the Americas.

The ischium bones of Mirischia’s pelvis were oddly asymmetrical, hence the species name ‘asymmetrica’, with one side featuring a hole and the other side only having a notch in the same position. The fossil specimen also had thin-walled bird-like bones, and soft-tissue impressions of intestines and a posterior air sac.

[quark-nova]

Tetanurae brought to its most exagerrated conclusion

Jurassic World and other media things: Have their raptors have ridiculously wiggly tails

Actual raptor tails:

the tail is so stiff the tendons became bones

[paleonativeart]

My new design on Spinosaurus of 2020 is finally done as well. This coloration are both based on marabou stork as a head and neck, and the body is based on espanola marine iguana which is referred as Christmas Iguana due the brightest colors instead of dull dark gray.