PermeateFree said:
mollwollfumble said:
PermeateFree said:
>>But the Cifelliodon discovery has wider implications than you might expect. First up, the creature wasn’t a pure modern mammal, but one step along the transition between reptiles and mammals. The fact that the skull was preserved in 3D (i.e., it wasn’t squashed flat by rock over time like so many fossils) helps scientists analyze it in more detail, using CT scans.
“By studying its anatomy and performing an evolutionary tree analysis, we found that Cifelliodon belonged to a long-lived and widespread group of early mammal relatives called haramiyidans,” says Huttenlocker. “The three-dimensional preservation of Cifelliodon highlights the primitive brain, palate and feeding structure of this special group and reinforces their position near the base of the mammalian family tree.”<<
https://newatlas.com/early-mammal-fossil-pangaea-breakup/54769
> wasn’t a pure modern mammal
Have to be careful here. The definition of “mammalia” was changed when “reptilia” was shunted aside in favour of “sauropsida”. As a result of the change, the “mammal like reptiles” such as cynodonts are now classed as full mammalia.
As is this species.
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Haramiyida
Family: Haramiyidae
Genus: Cifelliodon
Huttenlocker et al., 2018
Species: †Cifelliodon wahkermoosuch
Thanks. “Cifelliodon was found in the geological rock unit called the Yellow Cat Member, part of the Cedar Mountain Formation in Grand County, Utah. This rock unit dates to between 139-124 million years old. It was found alongside the remains of several dinosaurs – a large iguanodontian, a dromaeosaur, and an ornithopod – and parts of a crocodyliform.” That date makes it … early Cretaceous – either Barremian, Hauterivian, Valenginian, Ryazanian or Berriasian.
“The skull measures 70 mm in length, giving an estimated body mass of 0.91-1.27 kg”.
“Previously, scientists had suggested that the hahnodontid mammals belonged to the well-known group of mammals called multituberculates. However, examining the anatomy of Cifelliodon, Huttenlocker et al (2018) found it to be closely related to Hahnodon and Vintana, and placed them outside of Multituberculata and outside the crown mammals. This makes Hahnodontids a late surviving stem mammal group. It also suggests that there were greater links between the tetrapod animals across the continents in the Cretaceous.”
What’s the difference between a “stem mammal” and a “crown mammal”?
Hahnodon is known only from a single tooth in Morocco.
“Vintana sertichi is an early groundhog-like mammal dating from the Late Cretaceous, approximately 66 million years ago. Scientists found the lone fossil, a skull, on Madagascar’s west coast.”
Haramiyida – very many fossils are known, with finds dating back to the year 1840. “It is possible that haramiyids are ancestral to multituberculates, who survived until 44 million years ago, although the available evidence is insufficient to be conclusive.” “The youngest haramiyid fossil genus is Avashishta bacharamensis from the Maastrichtian (66 Ma) of India. Cretaceous haramiyids are previously known from the Early Cretaceous of Morocco, suggesting that these animals may have survived in gondwannan landmasses as relics. With a temporal range of at least 150 million years, they are the longest lived mammaliaform lineage.”
I can’t find out much more about the Haramiyida than is in the Wikipedia entry.
