Episode 151: Fossils with other fossils inside

Published: Dec. 23, 2019, 7 a.m.

b"Thanks to Pranav who suggested this week's amazing topic, animals that fossilized with the remains of their last meal inside!\\n\\nIndrasaurus with a lizard inside. Yum!\\n\\n\\n\\nBaryonyx:\\n\\n\\n\\nRhamphorhynchus (left, with long wing bones) and its Fish of Doom (right):\\n\\n\\n\\nThe fish within a fish fossil is a reminder to chew your food instead of swallowing it alive where it can kill you:\\n\\n\\n\\nThe turducken of fossils! A snake with a lizard inside with a bug inside!\\n\\n \\n\\nShow transcript:\\n\\nWelcome to Strange Animals Podcast. I\\u2019m your host, Kate Shaw.\\n\\nThis week we have a listener suggestion from Pranav, who has sent me so many amazing suggestions that he has his own page on the ideas spreadsheet. When he emailed me about this one, he just suggested cool fossils, but the links he provided had a really interesting theme that I never would have thought about on my own. This week we\\u2019re going to learn about some fossil animals that have fossils of their last meal inside them!\\n\\nWe\\u2019ll start with a recent discovery of a new microraptor species, Indrasaurus wangi, which lived about 120 million years ago. It was an interesting animal to start with, because it had arms that were very similar to bird wings, although with claws, but its hind legs also had long feathers that made it almost like a four-winged animal. It was found in 2003 in northeastern China, but when researchers were studying it in 2019 they found something amazing. Not only did it have an entire lizard skeleton where its stomach once was, showing us that it swallowed its prey whole, the lizard itself was a species new to science.\\n\\nWe know what else Indrasaurus ate because more Indrasaurus fossils have been found in the area, many of them so well preserved that its fossilized stomach contents have been preserved too. It ate mammals, birds, lizards, and fish\\u2014basically anything it could catch.\\n\\nAnother species that was similar to Indrasaurus, called Anchiornis, also called a four-winged bird-like dinosaur, was found with what appears to be a gastric pellet in its throat. The pellet contains the bones of more than one lizard and was probably ready to be horked up the way many carnivorous birds still regurgitate pellets made up of the indigestible parts of their prey, like bones, scales, and fur.\\n\\nThe fossilized remains of food inside a fossilized organism has a term, of course. It\\u2019s called a consumulite. It\\u2019s a type of bromalite, which is a broader term for any food or former food found in a fossilized organism\\u2019s digestive tract. The term bromalite also includes coprolites, which are fossilized poops.\\n\\nNaturally, it requires a high degree of preservation for consumulites to form, and a high degree of skill to reveal the often tiny and delicate preserved details. And consumulites are important because they let us know exactly what the animal was eating.\\n\\nConsumulites aren\\u2019t limited to prey animals, either. A small armored dinosaur, a type of ankylosaur, called Kunbarrasaurus, which lived around 115 million years ago in what is now Australia, was a herbivore. The type specimen of the species, which was described in 2015, was incredibly well preserved\\u2014almost the entire skeleton, most of its body armor, and the contents of its stomach. Paleontologists can determine not just what kinds of plants it had eaten\\u2014which include ferns and seeds\\u2014but how it was processing its food. Most herbivorous dinosaurs swallowed leaves and other plant parts whole, then crushed the food in a powerful gizzard or gizzard-like organ along with rocks or grit. The rocks helped break up the plant material, and we have lots of these rocks associated with fossilized dinosaurs. The rocks are called gastroliths and are usually worn smooth. But Kunbarrasaurus didn\\u2019t have any gastroliths, and the plant material was so well preserved that researchers could see the cut ends of the plants where Kunbarrasaurus had bitten them. And all the pieces were small."