Episode 7: Primates

Find Episode 7 in the same places as all the others: PodBean and iTunes!

This episode we are joined by special guest Ethan Fulwood, who helped us explore a group of animals you may be somewhat familiar with: Primates.

In the News:
Injuries of Ancient Predators
The fossils of saber-toothed cats and dire wolves at the La Brea tar pits reveal the perils of their distinct hunting habits. [News Article]
A Very Ancient Archosaur
Teleocrater is a newly-discovered, very old reptile that seems to sit right at the base of the dinosaur-pterosaur lineage of life, and might offer insights into the very earliest dino-cousins. [News Article]
Surprise Fruit-eating Bats
A living species of Mexican bat eats a surprising variety of food, including fruit! This might have implications for the evolution of different feeding styles. [The Paper]

Meet the Primates

There are over 200 species of primates in the world today, spread across the tropical regions of the globe. From the somewhat strange lemurs, lorises, galagos, and tarsiers; to the more familiar American monkeys, including tamarins, marmosets, capuchins, and more; and to the Old World monkeys, including baboons, macaques, and our very own group, the apes.

Primates
The incredible diversity of primates. Top: Tarsier, Baboons, Spider Monkey. Bottom: Lemur, Human, Orangutan. Images from Wikimedia by Kok Leng Yeo, Charles J Sharp, Petruss, Aerial Showgirls, & Tankinzinnia

Look at those pictures and you’ll find some very familiar characteristics. Short faces, forward-pointing eyes (binocular vision!), and very mobile and dexterous limbs, including our famous opposable thumbs (and toes in most species).

Primates also often have big brains, three-color vision (compared to two-color in most mammals), complex social structures, and high intelligence. And of course, more than most other animals, primates are built for an arboreal life among the branches.

Primate Skeletons
Top: Green monkey skull (by Didier Desouens). Bottom: Human skull (by Chris Dodds). Right: Squirrel Monkey skeleton (by Cliff)

Primate Evolution

Primates got their start shortly after the K-Pg Extinction. Through the Paleocene Epoch, we see abundant fossils of a group of very primate-like tree-dwellers called the Plesiadapiformes (including such famous fossils as Plesiadapis and Carpolestes). These strange little critters might be the closest cousins – or perhaps the ancestors – of primates.

In the Eocene (starting ~55 million years ago), true primates really take off in a world of rising temperatures. We see great diversity in two ancient primate groups: the adapiformes (including Darwinius and Notharctus) and the omomyids (such as Necrolemur). These groups spread all over the world, but when the Eocene draws to a close and the Earth begins to cool down, primates retreat to the tropics. These ancient groups will ultimately not make it to the modern day.

PrimateFossils
Left: Plesiadapis (by Ghedoghedo). Right: Darwinius (by Nobu Tamura). Bottom: Notharctus (by Claire Houck). Representing the three major groups of ancient primates and near-primates. All from Wikimedia.

Modern primate groups got started early, but remained pretty unimpressive until the Miocene Epoch (starting ~23 million years ago), when temperatures rose again. Here we see some major diversification of New World Monkeys and Old World Monkeys, especially apes.

When the Miocene comes to a close and the cooler temperatures of the Pliocene start to set in, one group of apes begins to outstrip the rest: the hominins. But that’s a story for another episode.

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