Before the asteroid completely changed the course of the Earth’s evolutionary course, the Earth filled up. Scaled and feathered dinosaurs, web-winged pterosaurs and as new Study Describes, the ancestors of modern mammals that dug into the Cretaceous soil found existence in old age.
Paper description Two newly identified species: Reptiles Fasciomanas sinensis And mammals Zyknodon chain, Both dating to almost northeast China which is 120 million years ago from today. The former was a reptile like a mammal A group called tritildontoids, and the latter is eutriconodontans, this multifaceted method stated that it was evolutionarily close to the common ancestor of modern marsupials and placental mammals. Both animals were less than a foot tall and they were diggers.
Tritildontides were commonly mammals: tHey it was probably warm bloody And there were several skeletal features, especially with their limbs, that mammals were more involved with than their reptile contemporaries.
“Each of the two represents the only known excavation species in its own group (Tritildontidus and Eutriconodontans, respectively); In other words, other members of their own group do not dig, “said Jin Meng, an archaeologist at the American Museum of Natural History in New York, in an email.” The common ancestor of mammals is probably not aging [digging] Lifestyle. “
As the reason for their digging, it could be a lot of things. Meng said avoiding dinosaurs and other predators, staying hot or cold at different times of the year, and eating can all be a factor in their survival. The fact that both animals were not closely related, even though they were coexisting in their ecosystem, suggests that such an old niche had developed, which was an effective way to bypass it.
The really interesting thing about these animals and thus the title of the paper worked with the elongated vertebral columns of the two diggers. F. synensis There were 38 spines, and Jay Chain 28. Mammals usually have 26 from neck to buttocks. Researchers are of the opinion that the increased number of vertebrates can be attributed to genetic mutations in the early stages of embryonic development, although it is so ancient that no answer to this genetic question remains unanswered.
“Animals that live in burrows have more virtuosity in them, probably making their bodies more flexible so that they can rotate backwards on narrower backs,” Meng said. “They move slowly so that their spine is stable; This is one of the reasons why they can change their cartilage columns. “
The other fossil features that the two fossils indicated were excavators, Included involved Limbs, Strong nozzles, and some nails are reminiscent of modern moles, which indicates that they will try to get rid of dirt.
Long extinct, the two animals depict a variety of life forms during the Cretaceous, including crowds of charismatic carnivorous dinosaurs that stole our attention. A reptile and a mammal, both were roaring uncontrollably as other animals were treating them.