Whilst looking at a scientific paper published earlier this year which featured the description of two new species of burrowing mammals from the Early Cretaceous of north-eastern China, team members came across a superb illustration of the types of mammals and mammaliamorphs associated with the famous Jehol biota. The artwork had been created by world-renowned palaeoartist Zhao Chuang and it depicts the biota associated with the Lower Cretaceous deposits associated with the Yixian Formation and Jiufotang Formation. What a stunning piece of art.

The Early Cretaceous Jehol biota with emphasis on mammaliamorphs.
The Early Cretaceous Jehol biota with emphasis on mammaliamorphs. Picture credit: Zhao Chuang.

Fossiomanus sinensis and Jueconodon cheni

The two new ancient ancestors of modern mammals were both burrowers, with powerful hands, claws to help with digging, compact bodies and short tails. Although they shared similar anatomical traits, – adaptations to life underground – they were not closely related. The slightly smaller Jueconodon cheni has been classified as a eutriconodontan, a distant cousin of modern placental mammals and marsupials, it was around 20 cm in length. Fossiomanus sinensis is a herbivorous mammal-like animal called a tritylodontid and was around 30 long.

One of the co-authors of the scientific paper, published in the journal “Nature”, Dr Jin Meng from the American Museum of Natural History (New York), commented:

The Early Cretaceous Jehol Biota has generated many well-preserved fossils that have furnished a great deal of information on the morphology and evolution of early mammals. The two new species expand the diversity of the mammaliamorph assemblage and increase its morphological disparity, as they show unequivocal evidence of convergent adaptation for a fossorial lifestyle.”

Jehol mammals Fossiomanus sinensis and Jueconodon cheni
Two new species of Early Cretaceous mammals were described from fossils found in north-eastern China. Fossiomanus sinensis (upper right) and Jueconodon cheni in their burrows. Picture credit: Zhao Chuang.

As well as reading about the diverse nature of the mammaliamorph biota associated with the Early Cretaceous Jehol ecosystem, we have the opportunity to admire the stunning artwork of Zhao Chuang. Fossils from north-eastern China have revealed that during the Early Cretaceous, the forests and lakes were home to a wide variety of different mammaliamorphs. The mammaliamorpha is defined as a clade of cynodonts including mammaliaforms and their close relatives. It is therefore a broader definition of early mammals than the mammaliaformes.