#kritosaurus

[tyrannoninja]

Kritosaurus at a Salt Lick

66 million years ago in Late Cretaceous North America, a herd of Kritosaurus navajovius gather around a salt lick in a jungle clearing. Licking minerals from the clay here provides these hadrosaurid dinosaurs with essential nutrients such as sodium, calcium, and zinc which helps with the animals’ physical growth. It’s a behavior many animals throughout the world carry out to this day.

[new-dinosaurs]

Coahuilasaurus lipani Longrich et al., 2024 (new genus and species)

(Type specimen of Coahuilasaurus lipani [scale bar = 20 cm], from Longrich et al., 2024)

Meaning of name: Coahuilasaurus = Coahuila lizard [in Greek]; lipani = for the Lipan Apache people

Age: Late Cretaceous (Campanian), around 72.5 million years ago

Where found: Cerro del Pueblo Formation, Coahuila, Mexico

How much is known: Partial skull of one individual. Skull fragments from at least one other individual may also belong to this species.

Notes: Coahuilasaurus was a hadrosaurid (duck-billed dinosaur). The type specimen was formerly considered a specimen of Kritosaurus navajovius, which is otherwise known from the southwestern United States. However, this specimen noticeably differs from Kritosaurus in several ways, such as having a strongly downturned tip of the lower jaw. The authors of a new study thus reclassify it as a new genus and species, and consider it likely more closely related to Gryposaurus. Coahuilasaurus is estimated to have been about 8 m long in total body length.

Reference: Longrich, N.R., A.A. Ramírez Velasco, J. Kirkland, A.E. Bermúdez Torres, and C.I. Serrano-Brañas. 2024. Coahuilasaurus lipani, a new kritosaurin hadrosaurid from the upper Campanian Cerro del Pueblo Formation, northern Mexico. Diversity 16: 531. doi: 10.3390/d16090531

[mineralsrocksandfossiltalks]

Wordplay Wednesday: Index Fossil

Trilobites have come up a bunch this month and on Monday I mentioned they were used to date certain rocks. We call these kinds of fossils index fossils.

Now, not everything can be an index fossil. There are some very important qualities needed to be considered an index fossil.

1.) They must be distinctive and easily recognizable.

Look at how easy it is to identify different trilobites (and this is an incredibly small selection of the thousands of types out there).

However, if you were to look at hadrosaurinae, it is very difficult to tell Kritosaurus from Gryposaurus from Brachylophosaurus.

2.) They must be widespread. Trilobites can be found on every continent including Antarctica. In contrast, hadrosaurs have not been found in Africa or Australia so they are not very widespread.

3.) They must be abundant. There are over 22,000 kinds of trilobites while there are only about 60 kinds of hadrosaurs. Not even a competition there.

4.) They must live in a limited amount of geologic time. That means they can only be found in like one stage rather than an entire Era. Each of the 22,000 trilobites out there has their own distinct time they lived. For example, Elrathia lived from 513-499 Ma while Walliserops lived from 407-388 Ma.

Some may argue that hadrosaurs have a fighting chance here. Gryposaurus only lived from 80-75 Ma. That's a short time. We could use them to date rocks. But guess who else lived within that time frame?

Maiasaura.

Kritosaurus.

Hadrosaurus.

Brachylophosaurus.

Corythosaurus.

The list goes on. So, as you can see, dinosaurs do not make good index fossils but trilobites make great ones.

Fossilize you later!

[a-dinosaur-a-day]

Ajnabia vs Tlatolophus

Factfiles:

Ajnabia odysseus

Artwork by @i-draws-dinosaurs, written by @zygodactylus

Name Meaning: Great Seafarer Stranger 

Time: 68 to 66 million years ago (Maastrichtian stage of the Late Cretaceous) 

Location: Upper member of the Couche III Formation, Ouled Abdoun Basin, north-central Morocco 

Ajnabia is an extremely small (possibly the smallest) hadrosaur, specifically a European lambeosaurine. Finding one in Morocco was a legitimate surprise discovery, since northern Africa was fully separated from Europe by ocean at the time. Known from parts of the jaw, most of what we know about it is inferred from its probable close relatives, the North African-European Maastrichtian hadrosaurs - though the crests of these animals are not well known, it is presumable they for the group would have been hollow and shaped in different ways to produce different sounds based on species, including Ajnabia. As in other hadrosaurs, it would have been robust, with long robust and stiff tails, muscular hind limbs with three toed feet, and strong slender forelimbs ending in weird hoof-like structures. They also had rows and rows of densely packed teeth built for grinding through a variety of vegetation. It probably got from Eurasia to Africa via oceanic dispersal, possibly even swimming from one landmass to another. At less than four meters long, it would have been dwarfed by its newfound neighbors, large dinosaurs such as the abelisaurid Chenanisaurus, and a yet-unnamed titanosaur. There were also, of course, azhdarchids in the form of Phosphatodraco and pteranodontid Tethydraco, and three separate types of Nyctosaurids - Alcione, Simurghia, and Barbaridactylus (you may recognize this lineup from a certain paleo doc). On the ocean side of things, mosasaurs, elasmosaurs, sharks, fish, and other marine life filled the seas to the brim, making it even more of a wonder that Ajnabia got over to Morocco safely! 

Tlatolophus galorum

Artwork by Joaquin Eng Ponce, written by @zygodactylus

Artwork by Joaquin Eng Ponce, written by Meig 

Name Meaning: Gazra and López’s Word Crest 

Time: 73 million years ago (Campanian stage of the Late Cretaceous) 

Location: Cerro del Pueblo Formation, Coahuila, Mexico 

Tlatolophus was a Lambeosaur - so another crested hadrosaur - from Mexico, a place that we don’t talk about the fossils of nearly enough! The most complete Lambeosaur known from Mexico, the skull and large portions of the skeleton are known, including the tail. At about 8 meters long, Tlatolophus had a tall skull and thick tail, and the usual hooved front feet of hadrosaurs. Its crest was long, low, and angled backwards, much like the glyph for “word” in Aztec writings - hence its name! Given the unique shape, it probably made a unique sound, different from other hadrosaurs. Interestingly, it actually seems to have been closely related to Parasaurolophus and its relatives, making it another member of the Parasaurolophini group! As a hadrosaur, it would have been a social animal, with behaviors such as communal nature and communication. The Cerro del Pueblo formation was a coastal ecosystem, filled with a variety of unnamed dinosaurs, but also Coahuilaceratops, Kritosaurus, Latirhinus, Velafrons, Paraxenisaurus (the first potential Deinocheirid from North America), as well as pterosaurs, turtles, fish, and multituberculate mammals. 

DMM Round One Masterpost

[darabeatha]

in my imagination, D.aybit visited Argentina and he liked alfajores and empanadas and the kritosaurus navajovius

[antiqueanimals]

Predatory Dinosaurs of the World: A Complete Illustrated Guide. Written and drawn by Gregory Paul. 1989.

Internet Archive

[i-draws-dinosaurs]

It’s another lightbox! I actually made this one first, but I forgot about it so here it is now! A Kritosaurus, separated from its herd, crosses a sequoia bridge through the forest. The lone herbivore continues to search for the safety of its group as evening falls. Being alone in a Campanian forest at night is not a good idea.

Thank you all so much for your enthusiasm about the last lightbox post, it’s something I really enjoy doing so I’m glad y’all like seeing it too! I’ve included another ‘process’ kinda photo with this one, so you can see all the different layers that make up this piece! This one has nine, I generally keep the layer count under ten because one you get up to that point the light just doesn’t really come through the paper any more so it’s pretty much pointless. This one had the added bonus of the foam board at the bottom of the scene kinda looking like the surface of a creek, which was not intentional but I think it looks nice!

[makairodonx]

A Mexican Kritosaurus

This saurolophine hadrosaur hailing from the Cerro del Pueblo Formation (73-71 million years ago) which is part of the Sabinas Basin in Mexico, was originally described as Kritosaurus sp. by Kirkland et al. in 2006, but was later described as an indeterminate saurolophine by Prieto-Márquez et al. seven years later. This Mexican kritosaur is unique for sporting a ndistinctively curved ischium, and at 11 meters or 36 feet long, this Mexican Kritosaur was 20% larger than other species of the genus Kritosaurus, making it one of the largest saurolophines ever documented from North America. It shared its coastal wetland habitat, which spanned the southern coast of Laramidia, with other large herbivores such as fellow saurolophine Latirhinus uitstlani, the lambeosaurines Velafrons coahilensis and Tlatolophus galorum, and the chasmosaurine ceratopsian Coahuilaceratops magnacuerna.

[tsaagan]

‘Beak lizards, who have strange head ornaments.

Top: Helmet lizard and hawk lizard.

Bottom: Cone lizard and crown lizard.’

Fortidsdyr I Farver, 1957 Finnish edition

Kai Petersen Illustrated by Verner Hancke

'Most extinct animals have only scientific names, Greek or Latin. Because of that the author of the original (Danish) edition invented Danish names for the animals. Finnish versions of those names have been used in this edition except for those (very rare) cases where an animal already has a Finnish name.'

[extinctworld-ua]

Huallasaurus

Huallasaurus — рід зауролофінових гадрозаврів з пізньої крейди Лос-Аламітоської формації в Аргентині (Патагонія). Типовий і єдиний вид — H. australis. Спочатку названий як вид Kritosaurus в 1984 році, він довго вважався синонімом Secernosaurus, перш ніж був визнаний окремим родом у дослідженні 2022 року, відмінним від інших представників Kritosaurini.

Повний текст на сайті "Вимерлий світ":

https://extinctworld.in.ua/huallasaurus/

[paleonativeart]

I’m back to drawing scaly hadrosaurid such as New Mexico’s Kritosaurus navajovius to celebrate the #nationaldinosaurday on this day. #kritosaurusnavajovius #kritosaurus #kritosaurini #naayéé #dinosauria #hadrosauridae #ornithopoda #sketchbook #paleoart #artistsoninstagram #artistontumblr #myart https://www.instagram.com/p/CAOZgvxlOdx/?igshid=1g7sjurs1wb9c

[tyrannoninja]

This unfortunate Kritosaurus navajovius is about to have a hungry Tyrannosaurus rex crunching down on its neck!

Most of the time, when you see a T. rex going after hadrosaurs in paleoart, the prey is Edmontosaurus. I wanted to shake things up a bit by having the unlucky hadrosaur be Kritosaurus, from the southern half of T. rex’s range, instead.

[dinoesculturas]

#Kritosaurus #Secernosaurus - Dibujo en grafito y lápiz blanco sobre papel gris / Graphite and white pencil over gray paper https://www.instagram.com/p/B6MJNhjlZ2s/?igshid=1lrqzlf97bw5w

[horrible-lizards]

Kritosaurus, 1910

[a-dinosaur-a-day]

Round Two: Tlatolophus vs Jakapil

Tlatolophus galorum

Artwork by Joaquin Eng Ponce, written by @zygodactylus

Name Meaning: Gazra and López’s Word Crest 

Time: 73 million years ago (Campanian stage of the Late Cretaceous) 

Location: Cerro del Pueblo Formation, Coahuila, Mexico 

Tlatolophus was a Lambeosaur - so another crested hadrosaur - from Mexico, a place that we don’t talk about the fossils of nearly enough! The most complete Lambeosaur known from Mexico, the skull and large portions of the skeleton are known, including the tail. At about 8 meters long, Tlatolophus had a tall skull and thick tail, and the usual hooved front feet of hadrosaurs. Its crest was long, low, and angled backwards, much like the glyph for “word” in Aztec writings - hence its name! Given the unique shape, it probably made a unique sound, different from other hadrosaurs. Interestingly, it actually seems to have been closely related to Parasaurolophus and its relatives, making it another member of the Parasaurolophini group! As a hadrosaur, it would have been a social animal, with behaviors such as communal nature and communication. The Cerro del Pueblo formation was a coastal ecosystem, filled with a variety of unnamed dinosaurs, but also Coahuilaceratops, Kritosaurus, Latirhinus, Velafrons, Paraxenisaurus (the first potential Deinocheirid from North America), as well as pterosaurs, turtles, fish, and multituberculate mammals. 

Jakapil kaniukura

Artwork by @i-draws-dinosaurs, written by @zygodactylus

Name Meaning: Deep Jawed Shield Bearer 

Time: 99 to 97 million years ago (Cenomanian stage of the Late Cretaceous) 

Location: Candeleros Formation, Neuquen and Mendoza, Argentina 

Jakapil is to nonavian dinosaurs as Annakacygna is to birds. This may seem extreme - what could possibly top the cup zoomy swan of filter feeding death - but Jakapil is a weird little dude. It was a bipedal armored dinosaur, similar to the Early Jurassic basal form Scutellosaurus - except, you’ll note, it lived a hundred million years later. At about 1.5 meters long, it was a small dinosaur, again similar to its relative from so long ago. It had rows of osteoderms on its body, and a predentary - unlike other early thyreophorans. It may have diverged from the main thyreophoran group in the Sinemurian, representing a lost lineage of bipedal armored forms that persisted (presumably in South America). However, its classification is a major debate among researchers - many features of the jaw are more similar to Ceratopsians than to Thyreophorans, indicating it may be an armored variant of an early Ceratopsian (which, would be, to say the least, wild) or a completely new clade of Ornithischian altogether! The large amount of wear on its teeth indicates it chewed its food, rather than sheering or chopping it - something only found in a few Ornithischian groups. It lived in a large desert environment, peppered with oases, and filled with a variety of other animals - fish, frogs, tuatara, snakes, turtles, mammals, and other dinosaurs like Andesaurus, Ekrixinatosaurus, Giganotosaurus, Buitreraptor, Alnashetri, and Bicentenaria. 

[saritawolff]

#Archovember Day 28 - Quetzalcoatlus lawsoni

While most people now know of the giraffe-sized Quetzalcoatlus northropi, the smaller species deserves much more credit. Most of what we know about the giant Q. northropi comes from lawsoni: northropi is known only from cervical vertebrae and some fragments of wing. We have filled in the rest using the anatomy of the smaller species, Q. lawsoni, of which much more material is known. For years Q. lawsoni wasn’t even named (as it was uncertain whether it was a juvenile or a seperate species). It was just known as Quetzalcoatlus sp. or “the smaller Quetzalcoatlus”. Finally, lawsoni was determined to be an adult and a separate species from northropi, and recieved a name in late 2021.

Even if it wasn’t the size of a giraffe, Quetzalcoatlus lawsoni was still a large, formidable azhdarchid! It had an estimated wingspan of 5 m (16 ft), body length of 3.5 m (11 ft), body mass of 65 kg (143 lb), and a long, sharp, pointed beak. It was native to Late Cretaceous North America, particularly Texas, where it coexisted with the other azhdarchid Wellnhopterus. It has been suggested that Quetzalcoatlus would have filled a similar niche to the modern Marabou Stork: a terrestrial scavenger and predator of small animals that could still fly in a pinch. Having unique fore and hindlimb proportions, Quetzalcoatlus seems adapted to a terrestrial lifestyle, and was even capable of “galloping.”

Alongside fellow azhdarchids Wellnhopterus and its larger cousin Q. northropi, Quetzalcoatlus lawsoni lived alongside the titanosaur Alamosaurus, the ceratopsids Bravoceratops and Torosaurus, the hadrosaurs Kritosaurus and Saurolophinae, the dromaeosaur Saurornitholestes, the troodontid Troodon, and of course, the tyrannosaurid Tyrannosaurus rex. It would have fed on a variety of small mammals, reptiles, and perhaps even birds and their eggs.