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b'What kinds of animals lived before dinosaurs evolved? What did they evolve into? Let\\u2019s find out!\\n\\nDimetrodon! Not a dinosaur! Not even actually a reptile:\\n\\n\\n\\nCotylorhynchus had a teeny head. I am not even exaggerating:\\n\\n\\n\\nMoschops had a big thick skull:\\n\\n\\n\\nLisowicia was the size of an elephant but looked like\\u2026well, not like an elephant:\\n\\n\\n\\nShow transcript:\\n\\nWelcome to Strange Animals Podcast. I\\u2019m your host, Kate Shaw.\\n\\nLots of people know about dinosaurs. Dinosaurs are really interesting. But do you know what animals lived before dinosaurs evolved? Let\\u2019s find out.\\n\\nIf you\\u2019ve heard of dimetrodon, you may think it\\u2019s just another dinosaur. It\\u2019s the animal that looks sort of like a huge lizard with a sail-like frill down its back. But not only was dimetrodon not a dinosaur, it went extinct 40 million years before the first dinosaur evolved.\\n\\nDimetrodon lived almost 300 million years ago and was a synapsid. Synapsid is a catchall term for a group of animals with both reptilian and mammalian characteristics, also sometimes called proto-mammals. The term synapsid also includes mammals, so yes, you are related to dimetrodon verrrrrrry distantly. You are more closely related to dimetrodon than you are to any dinosaur, let\\u2019s put it that way.\\xa0 Dimetrodon was an early synapsid, which are referred to as pelycosaurs.\\n\\nThe largest species of dimetrodon grew up to 15 feet long, or 4.6 meters, with some probably growing even larger. It had serrated teeth, a long tail, short legs, and a massive sail on its back. The sail is formed from neural spines, which are basically just really long prongs of bone growing from the vertebrae. The spines were connected with webbing, although possibly not all the way to the tip of the spines. Ever since the first fossil remains of dimetrodon were discovered in 1878, scientists have been trying to figure out what the sail was for.\\n\\nFor a long time the most popular theory was that the sail helped with thermoregulation. That is, it helped dimetrodon stay warm in cool weather and cool in warm weather by absorbing sunshine or releasing heat, depending on where dimetrodon was. If dimetrodon was chilly, it would angle its body so that lots of sunlight reached its sail, but if dimetrodon was hot, it would find a patch of shade or turn its body so that minimal sunlight reached its sail, allowing the blood vessels covering the sail to release heat into the atmosphere.\\n\\nThis is a pretty good guess, since many modern animals use something similar to help regulate body temperature. That\\u2019s why African elephants have such large ears. But more recent studies of dimetrodon\\u2019s sail show that it didn\\u2019t have a lot of blood vessels, as it would if it was for thermoregulation. These days paleontologists suggest the sails may have mostly been for display. Different species had differently shaped sails, and there\\u2019s some evidence that male and female dimetrodons of the same species may have had differently shaped sails too. It\\u2019s possible the sails were brightly colored or patterned during the breeding season.\\n\\nBut dimetrodon wasn\\u2019t the only early synapsid with a sail. Secodontosaurus had one too and resembled dimetrodon in many ways, including having a long tail and short legs. But where dimetrodon was chunky with a massive skull, secodontosaurus was much more slender with long, narrow jaws. It may have eaten fish. It probably grew up to nine feet long, or 2.7 meters, and it lived around 275 million years ago. It was related to dimetrodon, but paleontologists aren\\u2019t sure how closely it was related.\\n\\nThe largest pelycosaur, or early synapsid, was cotylorhynchus [ko-tillo-rinkus], which lived around 275 million years ago in what is now North America. It was a weird-looking animal. Weird, weird weird. Seriously, it was very strange. It grew to almost twenty feet long, or 6 meters, with a barrel-shaped body, great big legs, and a long tail. But its neck was very short and its head was tiny.'