▲A 62M-year-old skeleton sheds light on an enigmatic mammal(sciencedaily.com)
29 points by docmechanic 56 days ago | 3 comments
▲observationist 53 days ago
Not having images in an article like this is just wrong. Here's an article about the paper that comes with some great images.

https://www.earth.com/news/meet-mixodectes-pungens-prehistor...

▲thangalin 53 days ago
I wrote a coffee table photobook that includes scientific illustrations of a mammals, starting from the emergence of the mammaliaform (~193 million years ago) to ancestral apes (~10 million years ago). The similarities between Mixodectes at 62 Ma, the shrew-like mammal at 66 Ma, and that early mammalian predecessor at 193 Ma are a fine example of how slow evolution can be when ecological niches are otherwise occupied.

https://impacts.to/downloads/lowres/impacts.pdf

After the Chicxulub asteroid landed, it left us with an enigma: Why didn't reptiles rise again to fill those niches? PBS Eons has a video exploring the theory and the impacts of fungi on natural selection in the asteroid's wake.

https://www.youtube.com/watch?v=EPXbSx17030

▲travisgriggs 53 days ago
Squirrel!!
▲adrian_b 52 days ago
All early arboreal mammals looked like squirrels.

However the true squirrels are somewhat more distantly related to us, the tree shrews (Tupaia) are more closely related to us and the mammal described in the parent article is even closer to us in the line of evolution that has generated our ancestors (and the ancestors of apes, monkeys, lemurs and colugos).

▲numba888 52 days ago
> At almost three pounds (.4 kilograms), Mixodectes was quite large

Something is wrong here with the numbers..

▲stavros 52 days ago
Where did you see that sentence? They're missing the 1.
▲docmechanic 56 days ago
'For more than 140 years, Mixodectes pungens, a species of small mammal that inhabited western North America in the early Paleocene, was a mystery. What little was known about them had been mostly gleaned from analyzing fossilized teeth and jawbone fragments. But a new study of the most complete skeleton of the species known to exist has answered many questions about the enigmatic critter -- first described in 1883 by famed paleontologist Edward Drinker Cope -- providing a better understanding of its anatomy, behavior, diet, and position in the Tree of Life.'
▲heresie-dabord 53 days ago
"[The] findings show that they are close relatives of primates and colugos -- flying lemurs native to Southeast Asia -- making them fairly close relatives of humans."

"Two phylogenetic analyses performed to clarify the species' evolutionary relationships confirmed that mixodectids were euarchontans, a group of mammals that consists of treeshrews, primates, and colugos. While one analysis supported that they were archaic primates, the other did not. However, the latter analysis verified that mixodectids are primatomorphans, a group within Euarchonta composed of primates and colugos, but not treeshrews."

▲docmechanic 49 days ago
I had no idea that treeshrews are closely related to primates.