Scientists from the University of Kansas have identified a new species of extinct metatherian, Swaindelphys solastella. The species lived approximately 60 million years ago during the Paleocene epoch in what is now Big Bend National Park, Texas. This species was larger than other members of its genus, but comparable in size to a modern hedgehog.
Fossil remains, including molars and jaw fragments, were discovered in the Black Peaks Formation, an ancient river deposit in West Texas. These findings help to better understand the geographical distribution and adaptation of ancient mammals.
Scientists suggest that natural barriers, such as changes in river systems and mountain ranges, may have influenced the movement and distribution of species, including early marsupials and possibly primates.
The study also highlights differences between fossils found in the north (like Wyoming and Alberta, Canada) and those in the south, near the US-Mexico border. In the northern regions, the fossil record is more complete and allows for biostratigraphic analysis, while patterns are more difficult to trace in the south.