The prehistoric mammals of the air are bats, two early bats, Icaronycteris and Onychonycteris, and an even earlier protobat, which is hypothetical. Icaronycteris (“Icarus bat”) evidently hunted moths with echolocation about 50 Mya, which bats commonly do today. Onychonycteris (“clawed … Continue reading →

The prehistoric mammals of the water are pinnipeds (“fin foots”): the walrus-like Valenictus; the seal-like Enaliarctos; and the otter-like Puijila. Valenictus lived around 5 Mya, and it had no teeth other than its tusks. It evidently ate mollusks, like modern … Continue reading →

The prehistoric mammals of the land are two xenarthrans (“strange joints”) and an afrothere (“Africa beast”). The xenarthrans are a glyptodont and a ground sloth, while the afrothere is a mammoth. Glyptodonts (“carved tooth”) were giant armadillos that arose about … Continue reading →

The prehistoric arthropods of the land are Myriapoda (“countless feet”): a gigantic millipede, Arthropleura; a millipede relative, a pauropod; and a predatory centipede. Myriapods were the first land animals. They breathed air in and out through spiracles, which are holes … Continue reading →

The extinct arthropods of the water are chelicerates: a eurypterid, Hughmilleria; a Stylonurid eurypterid; and an early horseshoe crab, Lunataspis. Eurypterids walked on legs and swam with paddles. They also had chelicerae (“claw horns”), which were claws by their mouths that helped them … Continue reading →

The sauropsids of the water are a Plesiosaurus, a Pliosaurus, and an Odontochelys, an early turtle relative. Early in the Mesozoic Era, several sorts of lizard-like sauropsids swam and hunted in the water. While some lines of sauropsids led to … Continue reading →

The arthropods of the air are flying insects, a cockroach, Aphthoroblattina; a butterfly, Prodryas; and a dragonfly relative, Meganeura. Over 300 million years ago, insects appeared that could lay their eggs on land they could fold their wings behind them, … Continue reading →

In Clades: Prehistoric, the sauropsids of the land are dinosaurs, specifically a feathered Utahraptor (a theropod), an Apatosaurus (a sauropod), and a Stegosaurus (an ornithischian). The earliest dinosaur precursors were two-legged relatives of crocodiles, as were the first theropods, sauropods, … Continue reading →

In Clades, sauropsids of the air are represented by birds. Today’s birds all descend from a species of flying theropod dinosaur that lived before the Cretaceous-Tertiary extinction event of 70 million years ago. Unlike today’s common birds, these early birds … Continue reading →

The arthropods of the air are the clade Pterygota (“winged”), known as “winged insects” and represented here by a bee, a praying mantis, and a dragonfly. The bee represents Endopterygota (“inner winged”), the massively successful clade of insects that undergo … Continue reading →