Cy Marchant

'Peculiar' crocodile ancestor started life on four legs before learning to walk on two A "peculiar" ancient relative of the crocodile which experts believe began life on four legs before, in adulthood, it learned how to walk on just two has been revealed in a new study.

Fossil evidence suggests Sonselasuchus cedrus, an ancient crocodile relative, transitioned from walking on four legs as a juvenile to bipedal locomotion in adulthood during the Late Triassic. doi.org/hbrtbx

Results from the #paleostream!
Arctognathus with Arctops, Tanyka, Nannippus (with giant puffer fish) and Caninosaurus.

Contribute to PhyloPic—researchers use it a lot! www.phylopic.org/images/6a38b...

Scientists find 2 marsupial species, thought to have gone extinct 6,000 years ago, living in the forests of New Guinea The pygmy long-fingered possum and the ring-tailed glider, two marsupials believed to have died out thousands of years ago, are still alive in Papuan Indonesia.

Scientists find 2 marsupial species, thought to have gone extinct 6,000 years ago, living in the forests of New Guinea www.livescience.com/animals/land...

New paper! How weird could Permian animals get? Turns out, pretty weird. Meet the stem tetrapod Tanyka amnicola from the Pedra de Fogo Formation of northeast Brazil

royalsocietypublishing.org/rspb/article...

Pencil sketch. Foreground: two dacentrurine stegosaurs drinking from a stream in front of an embankment covered in a Gleichenia thicket. Equisetum grow by the streamside. In the background an adult and juvenile Stegosaurus wander through osmundaceous ferns. A Ptilophyllum-type bennettite stands from among the ferns.

Sketch: dacentrurine and stegosaurine stegosaurs coexisting in the Morrison Formation

Just published: A very unusual fish, described here as a new genus and species of loach, and the first groundwater-dwelling fish reported from Northeast India. Meet 𝑮𝒊𝒕𝒄𝒉𝒂𝒌 𝒏𝒂𝒌𝒂𝒏𝒂! Open access article here: www.nature.com/articles/s41...

Did some work for Dr. Dan Ksepka on some neat fossil birds. Nice to see the creative way the team that just published this paper put these two together.

"I believe In evolution, except for the whole Triassic period"

Hooray for clever scientific names inspired by Greek mythology! ✨

Very cool specimen with exciting implications. 🐦

New stem lepidosaurs from Vellberg, Germany: implications for palaeoecology in the early diversification of Lepidosauromorpha Lepidosauromorphs account for roughly a third of the living diversity of land vertebrates and yet their origin and early evolutionary history remain highly contentious. The fossil record of early l...

New paper alert! 🚨🥳 New lepidosauromorphs from Germany! This paper was 80% ready when Laura was born a couple weeks in advance.. since then it has been a good bit expanded, thanks to exchanges with colleagues at conferences and during review 😊 www.tandfonline.com/doi/full/10....

Comic. [2x2 chart. Top left quadrant: seem like dinosaurs x are dinosaurs. Silhouettes of dinosaurs stegosaurus, triceratops, tyrannosaurus, velociraptor, and long-neck dinosaur. Top right quadrant: seem like dinosaurs x are not dinosaurs. Silhouettes of mosasaur, quetzalcoatlus, dimetrodon, plesiosaur, and pteranodon. Bottom left quadrant: don’t seem like dinosaurs x are dinosaurs. Silhouettes of penguin, egret, ostrich, pigeon, falcon. Bottom right: don’t seem like dinosaurs x are not dinosaurs. Silhouettes of squirrel, stapler, plant, person, and bicycle.]

Dinosaurs And Non-Dinosaurs

xkcd.com/3204/

Haolong dongi, amazing new spiny (yes,really) iguanodontian from early cretaceous china #sciart

Result from the Joggins Formation #paleostream! This Canadian site is an absolute classic and even if you are not familiar with its name you probably know at least one of its major players...

Timeline of taxonomic history of Alwalkeria maleriensis

Alickmeron Sen & Ray, 2025 is an objective junior synonym of Alwalkeria Chatterjee & Creisler, 1994 @slvrhwk.bsky.social @ijreid.bsky.social
www.tandfonline.com/doi/full/10....

3-panel comic. (1) [Three small arthropods on ocean floor.] ARTHROPOD 1: Now that we’re multicellular, what are your plans? I’m gonna evolve little legs and swim around with them! ARTHROPOD 2: I’m gonna evolve sharp pincers and use them to crunch stuff! ARTHROPOD 3: I’m gonna evolve glands to make string from my butt and use it to construct elaborate geometric nets hundreds of times my size to catch other animals. (2) [Silence] (3) ARTHROPOD 1: *Dude.* ARTHROPOD 2: Can you *please* just be normal about this? ARTHROPOD 3: *What??!*

Early Arthropods

xkcd.com/3199/

The first page of the paper described in the post.

First paper of 2026 is out for #FossilFriday, and the first of probably several ornithischian papers over the next interval. Here my coauthors and I describe some tantalizing bits that suggest that ornithischian diversity in the Morrison Formation is higher than previously recognized.

And finally, many thanks to @semifossorial.bsky.social and @gondwannabe.bsky.social for their mentorship and for allowing my involvement in this incredible project. Thead by X. Jenkins below.

The origin of the tympanic fossa in reptiles revealed by a late Permian neodiapsid Living reptiles including turtles, crocodilians, birds and squamates are descended from a common ancestor among the Neodiapsida that lived in the late Permian c. 257 million years ago. Their origin w...

Link to paper: doi.org/10.1111/pala...

Needless to say, there is much more to come from the Permian reptiles of South Africa. Stay tuned! 🦎👀 (6/6)

Detailed life restoration of the head of Scyllacerta creanae based on reconstructions of its skull. Dorsal midline osteoderms are inspired by those reported in a specimen of Youngina capensis, a close relative. Artwork by @LiterallyMiguel

@literallymiguel.bsky.social did incredible work bringing Scyllacerta to life. This piece was featured on a poster I presented at last year's @societyofvertpaleo.bsky.social conference in Birmingham, UK. (5/6)

Historical terracotta relief of the mythical Greek monster Scylla, characterized as inhabiting a cavern, bearing many heads (variably described as dog- or monster-like), and having multiple rows of teeth in each skull. Many modern interpretations favor a more draconic/reptilian appearance. Couldn't be a better fit. 🐲 Image credit:Paul Hudson from United Kingdom, CC BY 2.0, via Wikimedia Commons. https://commons.wikimedia.org/wiki/File:British_Museum_-_Room_15_(16848840959).jpg

We chose the name "Scyllacerta creanae" for SAM-PK-K7710. The generic name is a portmanteau alluding to Scylla, the cavern-dwelling, many-headed, multiple-tooth-rowed monster of Greek myth, and 'lacerta', Latin for 'lizard'. The specific name honors Annelise Crean, the specimen's preparator. (4/6)

Digitally segmented skull of SAM-PK-K7710a (holotype) as preserved, with skull bones shown in distinct colors. Figured in mirrored right lateral (A), occipital (B), dorsal (C), and ventral (D) views. Scale bar = 5 mm.

Digitally segmented skull of SAM-PK-K7710c (referred) as preserved, with skull bones shown in distinct colors. Figured in mirrored right lateral (A), occipital (B), dorsal (C), and ventral (D) views. Scale bar = 5 mm.

Using high-resolution synchrotron μCT scans from the @esrf.fr, we were able to digitally segment each bone of the skulls (shown here in different colors), allowing their full anatomy to be studied in detail. (3/6)

SAM-PK-K7710, holotype aggregation specimen of Scyllacerta creanae, with each individual in a distinct color. Holotype (a) in yellow. Scale bar = 2 cm.

The Scyllacerta aggregation specimen was discovered in 1990 in Teekloof Formation outcrops in South Africa, now classified as part of the Endothiodon Assemblage Zone (~257 Ma). The individuals (a–f) were likely buried when the burrow they were inhabiting collapsed on them. (2/6)

Graphic illustrating the reconstruction process for Scyllacerta creanae (SAM-PK-K7710). The holotype aggregation specimen (left) comprises four skulls and at least six nearly complete skeletons preserved in lifelike positions. Using synchrotron micro-CT scans of the skulls, the bones could be segmented, digitally isolating them from the matrix and allowing their full morphology to be studied in detail (top center). Combining information from all four skulls, a reconstructed version could be assembled, depicting the likely life appearance (center, with each bone in a distinct color). This reconstruction can be used to make line drawings for science communication and skeletal reconstructions (bottom center). These reconstructions were the basis for a detailed life restoration of the head of Scyllacerta (bottom right, by @LiterallyMiguel). Despite its incredibly small size (top right, compared to a human hand), the known individuals were likely nearing full maturity.

Very excited to share Scyllacerta creanae, a new Permian stem-reptile from South Africa known from an aggregation of several individuals. This specimen provides unprecedented detail regarding the anatomy of the early reptile skull. 🦎

(1/🧵)

A small bit of grey rock containing the entwined and overlapping skeletons of several small lizard-like reptiles. On white foam with a scale bar.

This #FossilFriday we are pleased to have published the new younginid taxon Scyllacerta from the late Permian of South Africa 🇿🇦
This beautiful aggregation has the holotype and has been in the literature for 30 years as “juvenile Youngina”.
Photo taken before scanning at the @esrf.fr

Skull of Scyllacerta, reconstructed based on scans of four nearly complete skulls.

Introducing a new Permian reptile: Scyllacerta creanae

With a tympanic fossa on the quadrate and no lower temporal bar, Scyllacerta challenges long-standing ideas about when-and-how hearing evolved in reptiles 🦎👂

🔗 doi.org/10.1111/pala...

Top left: photograph of a grey slab containing multiple fossils, with vertebral columns clearly running vertically (SAM-Pk-K7710). This is a group of six Scyllacerta creanae individuals, including the holotype, a late Permian neodiapsid reptile from South Africa (scale bar at top right is 2 cm). Bottom right: a computer reconstruction of the skull based on three of the individuals in the fossil block. Scale bar at top right is 5 mm.

The origin of the tympanic fossa in reptiles revealed by a late Permian neodiapsid: new species Scyllacerta creanae onlinelibrary.wiley.com/doi/10.1111/... #FossilFriday @semifossorial.bsky.social @morphobank.bsky.social

Got encouraged to do one of these lol

#Portfolioday #paleoart

I love pretty scenery and accurately depicting animals in their enviroments!!! :P

Digital illustration of a brown skink with white markings with large pointy scales, it is eating wildflowers and there are vegetated sand dunes in the background.

Well this is as done as it's going to get. Tiliqua frangens, a megafauna skink from pleiocene and pleistocene australia with large pointy scales feeding on spring wildflowers. #palaeoart #palaeoart #reptile #lizard

These illustrations were largely referenced from 'research grade' iNaturalist observations of the respective genera, linked below:

S. serrata: www.inaturalist.org/observations...
C. smithii: www.inaturalist.org/observations...