Were there really two of South Africa's earliest crocodile relatives, or just one?

By using state-of-the-art CT and synchrotron X-ray imaging to peer inside 200-million-year-old fossils without damaging them, we solved a long-standing evolutionary mystery. Our results show that the enigmatic species Erythrochampsa longipes is not a distinct animal after all, but belongs to the already known genus Protosuchus, resolving decades of taxonomic uncertainty. We also found that these early crocodyliforms grew slowly, reinforcing previous evidence that the crocodile lineage underwent a major evolutionary slowdown in growth very early in its history. Together, these findings refine the family tree of the earliest crocodile relatives and provide new insights into how the ancestors of modern crocodiles evolved.

Figure: Bone histology of 'Erythrochampsa' showing slow growing lamellar bone with numerous growth marks interrupting the bone tissue.