We are both mammals, what animal can both life forms trace their lineage back to?
I’ve found on Wikipedia:
Middle Cretaceous
Which has the additional trivia perk of being a word with four consecutive vowels, none of them silent nor diphthongs.
Not the Centaur?
Other way round. Humans and horses are the ancestors of centaurs.
So what did the MRCA boreoeutherian look like. An undistinguished rodenty thing, I suppose.
No-one has found a fossil of one yet, though this 2013 image by Carl Buell seems to be an extrapolation of what it may have looked like.
Also you can search for images of Eomaia, a somewhat earlier mammal that has been found, and looks a bit similar.
If no one knows what they looked like, how do we know Eomaia “looks a bit similar?”
We know because we have a few fossils of very early placental mammals, and they all tend to be small and rodent-like. We can be virtually certain of that, because few if any larger land animals survived the Chixculub impact event. So the MRCA of horses and primates can’t have looked much different from any known ancestral mammal of the same period.
I think it’s similar to what historic linguists do in reconstructing dead languages. For example, from working backwards through known sound changes in various Germanic languages, they can offer a reasonable approximation of Proto-Germanic. And in much the same way they can work their way back to PIE. The difference is that paleontologists do have a few specimens to begin with, while linguists do not, in the case of languages that died out before the advent of writing.
They’ve named an animal they don’t even have direct evidence for? How strange.
ETA: didn’t see SoPs post.
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isn’t the -eu- a diphthong?
We do have direct evidence for the existence of this animal: Humans and horses both indisputably exist, and so their common ancestor must.
That’s not direct evidence. That’s logical inference.
Eh, what do you count as direct? If you see a live animal prancing about, you’re just inferring its existence from the pattern of photons hitting your retina. If something that comes from the animal (in this case, the photons) is enough to be considered “direct”, then why isn’t something else that comes from the animal (its descendants) direct?
To clarify, the animal shown in the Science article is not named. It is a composite based on the characteristics of its descendants.
Eomaia is based on an actual fossil, but it is a little farther down the family tree of placentals.
Boreoeutheria is not a single species, but a name for the clade that includes the ancestors of horses and primates.
Without getting into semantic nitpicking, let’s say we don’t have physical evidence of the ancestor itself.
Don’t judge me.
Are you being serious?
As well as all their descendants, extinct or extant. We are boreoeutherians.
Can mitochondrial DNA be used to determine when horses and humans split apart? How many MYA would that have been?
From the link in the first reply to this thread: