In the late Carboniferous and early Permian periods, around 307 to 280 million years ago, a fascinating discovery was made in Namibia that challenges our understanding of early tetrapod evolution. A giant salamander-like predator, named Gaiasia jennyae, was discovered in high-palaeolatitude deposits. This creature was not only larger than any previously described digited stem tetrapods but also had a unique phylogenetic relationship with the Carboniferous Colosteidae from Euramerica.
Gaiasia jennyae was first discovered in 2015, and since then, several large, semi-articulated skeletons have been found. The fossils reveal that this predator had a skull with a loosely articulated palate, a broad diamond-shaped parasphenoid, and a posteriorly projecting occiput. Its dentary and coronoid fangs were enlarged and interlocking, making it an effective hunter in its ecosystem.
Despite the harsh conditions of the Namib desert during that time, a rich vertebrate community was flourishing. Fish fossils found alongside Gaiasia suggest that the region was relatively well populated. The discovery of this giant predator challenges previous hypotheses regarding global tetrapod faunal turnover and dispersal at the Carboniferous--Permian transition.
The phylogenetic analysis places Gaiasia within the tetrapod stem group as the sister taxon of the Carboniferous Colosteidae from Euramerica. This finding points to a more global distribution of continental tetrapods during this time, which requires reconsideration of previous hypotheses.
Gaiasia jennyae is not only significant for its size but also for its unique relationship with the Carboniferous Colosteidae. This discovery sheds new light on the early evolution of tetrapods and challenges our understanding of their distribution during this time period.
The exact location where Gaiasia jennyae was discovered is not specified in the provided sources, but it is mentioned that the fossils were found in Namibia. The discovery was made by researchers from various institutions, including the University of Buenos Aires and Jennifer Clack from the University of Birmingham.
The discovery of Gaiasia jennyae challenges previous hypotheses regarding early tetrapod evolution and distribution. It also highlights the importance of continued research in this area to better understand our planet's biosphere.