Anthracodromeus longipes was an early reptile* that lived in what is now Ohio, USA, during the late Carbonifeorus about 307-305 million years ago.
(*or possibly a very reptile-like stem–amniote)
Around 20cm in total length (~8″), it had a rather lizard-like shape with a long body and a short tail. The digits on all four of its limbs were highly elongated with hooked claws, which appears to have been an adaptation for climbing.
It inhabited a coal forest dominated by lycopsid trees and seed ferns, and as one of the earliest known tetrapods to develop climbing behavior it would have had some ecological advantages over its relatives, being better able to escape from predators and access new food sources.
References:
- Carroll, R. L., and Baird, D. “Carboniferous stem-reptiles of the family Romeriidae.” Bulletin of The Museum of Comparative Zoology 143 (1972): 321–363. https://archive.org/details/biostor-696/mode/2up
- Mann, Arjan, et al. “Digit and ungual morphology suggest adaptations for scansoriality in the late Carboniferous eureptile Anthracodromeus longipes.” Frontiers in Earth Science 9 (2021): 675337. https://doi.org/10.3389/feart.2021.675337
- Simões, Tiago R., et al. “Successive climate crises in the deep past drove the early evolution and radiation of reptiles.” Science Advances 8.33 (2022): eabq1898. https://doi.org/10.1126/sciadv.abq1898
- Wikipedia contributors. “Anthracodromeus” Wikipedia, 09 Jun. 2024, https://en.wikipedia.org/wiki/Anthracodromeus