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.
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.
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).
'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.'
"[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."
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...
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
Squirrel!!
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).
> At almost three pounds (.4 kilograms), Mixodectes was quite large
Something is wrong here with the numbers..
Where did you see that sentence? They're missing the 1.
'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.'
"[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."