The ‘Amphimoschus’ is a mysterious ruminant that has been New fossils have been discovered that could reveal key factors about evolution of the Miocene ruminants, as the anatomy has been reconstructed and the kinship relationships of the species established.
A recent study reveals important aspects of the enigma Amphimoschus, a ruminant that lived in Europe during the Miocenebetween 17.5 and 13.8 million years ago. The research, in which the Institut Català de Paleontologia Miquel Crusafont (ICP), the National Museum of Natural Sciences (MNCN-CSIC) and the Universities of Alcalá (UAH) and Zaragoza (UNIZAR) participate, has reconstructed the relationship between anatomy and relationships of Amphimoschus and provided information on the appearance of the cranial appendages of ruminants. This work was made possible thanks to fossils found at the French sites of Artenay, Aerotrain and Thenay, loaned to researchers by the Museum Nationale d’Histoire Naturelle, Paris, France.
Amphimoschus: a very special cervid
The analyzed remains have allowed the scientific team to learn for the first time in 150 years the postcranial skeleton of this animal described in 1873, of which only skull and dental fossil remains were available. The results suggest that this ruminant without cranial appendages occupied a basal evolutionary position within the cervoid group, that is:Ruminants are most closely related to modern deer. This research challenges previously widely accepted hypotheses that linked Amphimoschus to other lineages within ruminants.
“We were able to confirm this with the added data from the postcranial skeleton Amphimoschus is not related to cattle as previously thought, but it is rather a basal member of the cervoids,” explains Israel M. Sánchez, researcher at the ICP. “Thanks to phylogenetic analyses, we have managed to redraw the evolutionary tree of ruminants and identify the three major lineages to which the current groups belong: Giraffomorpha, Cervidomorpha and Bovidomorpha,” adds MNCN researcher Juan López Cantalapiedra.
The anatomy of this ruminant’s legs suggests that it could have lived in swampy or semi-aquatic environments, as they resemble those of some current species, such as the African sitatunga antelopes, which are adapted to this type of habitat. Like these antelopes, Amphimoschus had stylized legs with elongated hooves and very long fingers that opened obliquely, allowing this ruminant to move without difficulty on the very soft and plastic substrates typical of swampy environments. The investigation also allowed it estimate the body size of Amphimoschuswhich would have weighed between 36 and 47 kilograms, slightly larger than a current roe deer, placing it among the medium-sized ruminants of its time.
This work represents a new step in understanding the evolution of cranial appendages in ruminants, one of the most complex and current topics in mammalian paleobiology. “The absence of horns in Amphimoschus is an interesting example of how some ruminant lineages have diversified without evolving the characteristic cranial structures we today associate with many members of this group, and is also evidence that the debate over the single or multiple origins of ruminant cranial appendages is far from closed. highlights Sánchez.
“Besides, we have opened new approaches to study its origins of the periodic regeneration of deer antlers. It is possible that the eternal, unbranched appendages preceded the antlers, as our results show, adds Beatriz Azanza, researcher at the University of Zaragoza.
Thanks to the study of fossilsscientists are able to determine the physical appearance of a studied species, its habitat, its feeding and breeding habits, and even the kinship ties it has with other species, whether similar or not.