Cynodonts – Primitive ‘mammals’ – By Vincent Sheppard
3 most interesting facts about your creature:
- Early, mammal-like creatures were warm blooded vertebrates that suckled their young and in general did not lay eggs. They date from the Triassic and are about the same age as the dinosaurs. But throughout the Mesozoic they were insignificant creatures, no bigger than cats. Their fossils are extremely rare. The oldest known mammal-like creatures lived during late Triassic times, living in the shadows during the age of the reptiles. Tiny, primitive, and sometimes quite bizarre, these creatures are the precursors of everything from deer to humans.
- The earliest evidence on the Jurassic Coast comes from the Middle Jurassic. The evidence is minimal represented from a scattering of minute teeth hidden amongst smashed and compacted seashells that make up the rock called Forest Marble. Storms may have swept these mammal-like creatures offshore into the shell banks. The fragile bones did not survive but the hard teeth did and were fossilised. Finds are very rare and involve processes of dissolving the rocks in acid, washing, sorting, and viewing under microscopes to reveal teeth which are only a few millimetres across. There are only a few locations in Britain where the fossil remains of these animals are found.
- By the early Cretaceous mammals had become more diverse. They were still small and were predated by the giant reptiles of the time. The Purbeck rocks contain tiny fragments of jaws and teeth, some less than 1mm across. Samuel Beckles in 1850 led the discovery of a great many specimens from Durlston Bay. It was painstaking work, passing sediment through sieves and picking out pieces via microscope by hand. Beyond this point there are no more primitive fossil mammals. They lived a quiet life not knowing that their arch enemy was about to be made extinct, they would then have the chance to flourish. Many new species have since been discovered in Purbeck, possibly 100 valid named species within a very limited geographical area. This indicates they were living in very close proximity.
Something you found surprising in your research
New fossil finds of complete well-preserved skeletons in rare fossil beds in China is showing that the long-standing view that early mammals were primitive, shrew-like insectivores, overshadowed by the dinosaurs, might not be true. There have been findings of mammal predators the size of badgers, possibly feeding on baby dinosaurs. Other beaver-like fish eaters have been discovered, showing that mammals did more than just live under the feet of their reptilian co-inhabitants.
Why should people vote for your creature?
Would we not want to see the fossil of an animal that has ultimately led to the evolution of humans become one of our Big Five fossils? Our ancestral primitive relatives had very difficult beginnings trying to survive in the shadows of the giant reptiles. New fossil finds on the Jurassic Coast and around the world are providing new information on how these animals evolved, not knowing that their time would come after the dinosaurs became extinct and the opportunity for them to dominate evolution would begin.