#parareptile

Painting of Scutosaurus and Inostrancevia (1966) by Zdeněk Burian

Scutosaurus ("shield lizard") is an extinct genus of pareiasaur  paraeiasaurparareptiles. Its genus name refers to large plates of armor scattered across its body. It was a large anapsid reptile that, unlike most reptiles, held its legs underneath its body to support its great weight. Fossils have been found in the Sokolki Assemblage Zone of the Malokinelskaya Formation in European Russia, close to the Ural Mountains, dating to the late Permian (Lopingian) between 259 and 252 million years ago...

https://en.wikipedia.org/wiki/Scutosaurus

Inostrancevia is an extinct genus of large carnivorous therapsids which lived during the Late Permian. The first-known fossils of this gorgonopsian were discovered in the context of a long series of excavations carried out from 1899 to 1914 in the Northern Dvina, Russia. Possessing a skull measuring approximately 40 to 60 cm (16 to 24 in) long depending on the species, all for a body length reaching 3 to 3.5 m (9.8 to 11.5 ft), Inostrancevia is the largest known gorgonopsian...

The Manicouagan Impact, Late Triassic, Quebec, Canada

This impact, involving an asteroid about 5 km long in diameter, is the sixth largest impact in the history of the earth. This piece depicts a Hypsognathus (left) and a Jupijkam (right) witnessing the meteorite impact. Despite being in what is now modern day Nova Scotia, the piece shows the sheer scale of the impact that it can be seen from so far away yet can still tower over the horizon. Nowadays, the impact crater, now known as Lac Manicouagan, can be seen from space and is sometimes called "The eye of Quebec"

By Ashley Patch

Etymology: High Jaw 

First Described By: Gilmore, 1928 

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, Diapsida?, Parareptillia, Procolophonomorpha, Ankyramorpha, Procolophonia, Procolophonoidea, Procolophonidae, Leptopleuroninae, Leptopleuronini 

Time and Place: Between 228 and 202 million years ago, from the Carnian to the Rhaetian of the Late Triassic

Hypsognathus is known from a wide variety of formations, including the Wolfville and Blomidon Formations of Nova Scotia, the New Haven Formation of Connecticut, and the Passaic Formation of New Jersey.

Physical Description: Hypsognathus was a Parareptile, a group of odd creatures much more common in the Permian but had their last hurrah during the Triassic. These animals were some of the most varied and fascinating creatures of their time, including some of the first bipeds, first megafauna, and first aquatic reptiles. In the Triassic, most looked like your generic tetrapod - lizards, except without their specializations and long tails; salamanders but with scales. Some, however, kept doing weird things, including our friend Hypsognathus here. Hypsognathus was about 33 centimeters long, with stocky limbs and a thick trunk. Its head was almost half as wide as the body was long at 12.5 centimeters, and it wasn’t very mobile (or kinetic) - instead, fixed in place for extra support and sturdiness. Notably, Hypsognathus had extensive spikes and protrusions coming off of its head to the sides and down on the face, making it look rather monstrous from the front. These spikes may have even been longer than the fossil indicates, covered by keratin for display purposes. Its jaw was curved upwards, giving it a weird sort of permanent smile, and it had giant teeth protruding from its mouth. These teeth were blunt and thick, allowing for strong mashing of food. These teeth were also fascinating because there was clear tooth replacement, usually alternating - in the sequence of ABABABAB, the A’s would get replaced, and then the B’s. The rest of its body was fairly standard for a Procolophonid - with short, splayed out legs for walking slowly and from side to side; wide and thick fingers and toes for gripping the ground; and a short stubby tail not used for much at all. It would have probably been covered in something akin to scales, and well adapted for dry conditions as a result. 

Diet: Hypsognathus was an herbivore, feeding on high-fiber, tough plant material. 

Behavior: Hypsognathus was, more likely than not, a burrowing animal. The lack of kinesis in the skull allowed it to use it like a shovel, which may have been one of the uses of the spikes on its face. It could then dig into the ground to hide from predators, burrowing deep and not worrying about the fact that the rest of its body is relatively unprotected since it is being hidden by the dirt. This also explains the lack of ornamentation elsewhere on the body, and its squat and short structure. A long tail, or long limbs, would not have aided in hiding in the dirt! In addition, those wide and thick fingers and toes would have helped in kicking up dirt and escaping from predators quickly. The spikes may have also been able to anchor Hypsognathus within the burrow itself, preventing it from being dug out by a small predator. These spikes would have also been decent as display structures, with longer or more ridiculous looking ones appearing Fancy to other Hypsognathus. This could have been added on to with more keratin sheaths, reflecting the ability of an individual Hypsognathus to waste energy - and burrow space - on more elaborate horns because it was doing so well. It would then emerge from the burrows to feed on roughage and tough plants - though it may have been able to feed on roots and tubers underground as well. Given it could have used the horns for display, it was probably at least somewhat social; however, we have no idea how much or if it took care of its young, or had any other complex behaviors. Juvenile and young specimens are known, and they also have spikes, so if they served for communication, social life may have been a part of youth as well as adulthood. 

Ecosystem: Hypsognathus was a consistent feature of Northeastern North America during the Late Triassic, present in a variety of environments and ecosystems along the geologically active area that would eventually open up to begin forming the Atlantic Ocean. It generally favored sandy beaches lining seasonal lakes and rivers, with a variety of coniferous trees and swamp trees rooted in the lake. There were also ferns, cycads, and plankton abundant around and within the water. There were also proto angiosperms! While Hypsognathus lived with a wide variety of animals, some creatures kept popping up over and over again - the Aetosaur Stegomus, Phytosaurs such as Belodon and Rutiodon, Rhynchosaurs like Scaphonyx and Colobops, predatory Pseudosuchians such as Erpetosuchus and Rauisuchians, the weirdo Tanystropheid Gwyneddichnium and the Allokotosaur Teraterpeton, other Procolophonids like Scoloparia and Acadiella, the Temnospondyl Metoposaurus, the Cynodont Arctotraversodon, and there were also early dinosaurs and late Dicynodonts (though only footprints were preserved). In fact, Hypsognathus is most commonly preserved alongside footprints, lending credence to the idea that it would burrow in wet, sandy places, and get trapped and preserved there in the same events that preserved the prints. 

Other: This strange burrower with a spikey head was a very successful animal - it was found all over Eastern North America, throughout the Late Triassic, and seems to have only gone extinct because of the end-Triassic extinction. This is notable, because it is one of the last surviving Parareptiles, ever. The other Parareptiles of the Triassic were also small, squat lizard-like burrowers, many with interesting head ornamentation as well. While the heyday of Parareptiles was behind them, they managed to put on an excellent (and adorable) final act. In fact, morphological diversity of Parareptiles went down from a wide variety of shapes and forms and lifestyles to just one, the Procolophonids like Hypsognathus. This makes Hypsognathus a unique example of an ancient lineage, survivors of one Mass Extinction just to be finished off by another. 

~ By Meig Dickson

Sources Under the Cut

Bunostegos ("knobbly [skull] roof")

... is an extinct genus of pareiasaur parareptile from the Late Permian of the Agadez Region in Niger. The type species, Bunostegos akokanensis, was named from the Moradi Formation in 2003. It was a cow-sized animal with a distinctive skull that had large bony knobs, similar in form to those of other pareiasaurs but far larger. The species appears to have lived in a desert in the centre of the supercontinent of Pangaea.

Analysis of the limb bones (including the scapulocoracoid, humerus, radius, ulna, pelvis, and femur) was published in 2015, and revealed that Bunostegos walked upright on four limbs, with the body held above ground. This new information directly suggests that it could be the first tetrapod with a fully erect gait...

Read more: https://en.wikipedia.org/wiki/Bunostegos

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This new fossil of a parareptile is called Carbonodraco lundi. COAL DRAGON (or Carbon Dragon)!!

The Lundi comes from Richard Lund, the paleontologist of the Carnegie Museum who discovered the fossil.

A sort of parareptile, a product of an alternative evolution from the first terrestrial amphibians, resulting in a form that is neither bird, nor mammal, nor reptile as we know it. This is a chunky plant eater, inspired by the real-life fossil animal, Cotylorhynchus.