In evolutionary terms, islands are the stuff of weirdness. It is on islands where animals evolve in isolation, often for millions of years, with different food sources, competitors, predators, and parasites … indeed, different everything compared to mainland species. As a result, they develop into different shapes and sizes and evolve into new species that, given enough time, spawn yet more new species.
Such is the case with the discovery of a new, bizarre 66-million-old mammal in Madagascar by a team of international researchers led by Dr. David Krause, senior curator of vertebrate paleontology at the Denver Museum of Nature & Science and professor emeritus at Stony Brook University, where part of the research was done. The discovery of this opossum-sized mammal that lived among dinosaurs and massive crocodiles on the fourth largest island on Earth was announced today in the journal Nature. Dr. James B. Rossie of Stony Brook University is one of the study’s co-authors. The late Yaoming Hu of Stony Brook University was also a co-author.
The finding of the new mammal, called Adalatherium, which is translated from the Malagasy and Greek languages and means «crazy beast,» is based on a nearly complete skeleton that is astoundingly well preserved. The skeleton is the most complete for any Mesozoic mammal yet discovered in the southern hemisphere.
Krause said that, «knowing what we know about the skeletal anatomy of all living and extinct mammals, it is difficult to imagine that a mammal like Adalatherium could have evolved; it bends and even breaks a lot of rules.»
In fact, although a life-like reconstruction might lead one to think that Adalatherium was a run-of-the-mill badger, its «normality» is literally only skin deep. Below the surface, its skeleton is nothing short of «outlandish.» It has primitive features in its snout region (like a septomaxilla bone) that hadn’t been seen for a hundred million years in the lineage leading to modern mammals.
«Its nasal cavity exhibits an amazing mosaic of features, some of which are very standard for a mammal, but some that I’ve never seen in anything before,» Rossie declared.
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