Porolepiform and lydekkerinid (Patreon)

While preparing the next Tet Zoo article on amphibian evolution I discovered - much to my surpise - that I don't have a porolepiform sarcopterygian. So now we have the Holoptychius you see here. Thanks to complete, fully articulated specimens known from Quebec, we know exactly what this animal looked like, so I merely copied those fossils. This is a big, chunky predator between 50 cm and 2.5 m; the individual shown here is meant to be c 1 m long. I drew in the scales but then opted to mostly give the animal a mottled, muddy look typical of benthic ambush predators. I still need to do several other porolepiforms AND go back and give colour schemes for all the lungfishes - I think I shared the lungfishes here before...

The plan to draw all the temnospondyl lineages I need continues with this Lydekkerina, an Early Triassic lydekkerinid from India and South Africa. It's 50-100 cm long, skull length c 10 cm. Most diagrams illustrating the skull make lydekkerinids look utterly flat-headed with dorsally facing orbits but 3d skulls figured by Jeannot et al. (2014) show a sloping snout, tall skull deck, and orbits that are directed dorsolaterally: all of that is depicted here, and it gives the animal a more 'terrestrial' look than the flat-headed, cylotosaur-like appearance otherwise expected.  

I have been resisting the urge to show the teeth fully visible, even though they are in fossil skulls. My thinking is that soft tissues around the jaw edges would mostly obscure them - we have been underestimating the extent of these tissues.

Little is known of the poscrania other than that the ribs are robust and hence that the body would have a robust, rotund appearance which I tried to depict. Limb configuration, digit number and tail form is illustrated as would be expected for a stereospodyl and likewise on skin texture: there would, presumably, be scales embedded within the epidermis but they would not be obvious on the outside. Instead, a rough, partly cornified epidermis that looks acceptable for a reasonably big amphibious animal is depicted.

The colouring is hypothetical and I didn't want to do anything that looked too crazy. Lydekkerinids would need to be somewhat cryptic in view of the much larger predatory temnospondyls that shared their habitats. Having said that, I arbitrarily opted to put a bit of a pattern on the head and jaw, both to help break up the animal's shape and to hint at the idea of aposematic patterning - "keep away, I snap".