Dietary specializations and diversity in feeding ecology of the earliest stem mammals

  title={Dietary specializations and diversity in feeding ecology of the earliest stem mammals},
  author={Pamela G. Gill and Mark A. Purnell and Nick Crumpton and Kate Robson Brown and Neil J. Gostling and Marco Stampanoni and Emily J. Rayfield},
The origin and radiation of mammals are key events in the history of life, with fossils placing the origin at 220 million years ago, in the Late Triassic period. The earliest mammals, representing the first 50 million years of their evolution and including the most basal taxa, are widely considered to be generalized insectivores. This implies that the first phase of the mammalian radiation—associated with the appearance in the fossil record of important innovations such as heterodont dentition… 

The earliest-known mammaliaform fossil from Greenland sheds light on origin of mammals

The earliest-known mandibular fossil of a mammaliaform with double molariform roots and a crown with two rows of cusps from the Late Triassic of Greenland is described and indicates that teeth with two roots can better withstand stronger mechanical stresses like those resulting from tooth occlusion, than teeth with a single root.

Phylogeny, function and ecology in the deep evolutionary history of the mammalian forelimb

This work quantitatively compared the forelimb shapes of the multiple fossil synapsid radiations to a broad sample of extant Mammalia representing a variety of divergent locomotor ecologies and indicates that eachsynapsid radiation explored different areas of morphospace and arrived at functional solutions that reflected their distinctive ancestral morphologies.

Mesozoic mammals of China: implications for phylogeny and early evolution of mammals

  • J. Meng
  • Environmental Science, Geography
  • 2014
The superb specimens from nearly all major groups of Mesozoic mammals in China provided a great amount of information that contributed to understanding on some major issues in phylogeny and the early evolution of mammals, such as divergences of mammals and the evolution of the mammalian middle ear.

Untangling the Multiple Ecological Radiations of Early Mammals.

The Late Triassic Record of Cynodonts: Time of Innovations in the Mammalian Lineage

The Late Triassic constitutes a pivotal time lapse, marked by an expansion of the geographical distribution and diversification of cynodonts, and summarizes the main morphologies represented in the lineage, including Mammaliaformes, a key group in the authors' understanding of the early evolution of mammals.

Tetrapod Teeth: Diversity, Evolution, and Function

This chapter presents a survey of dental form and function in both stem- and crown-tetrapods, and gives the reader a sense of the extraordinary range of adaptive solutions among the tetrapods to the challenges associated with food acquisition and processing.

Dinosaurs, But Not Only: Vertebrate Evolution in the Mesozoic

If we imagine walking through Mesozoic lands, we would be able to observe vertebrates with peculiar combinations of morphological traits, some of which would seem to be intermediary to animals seen

Jaw shape and mechanical advantage are indicative of diet in Mesozoic mammals

It is found that these metrics can be used to distinguish dietary groups for most extant mammals, and to infer diet in Mesozoic taxa, and set the basis for future ecomorphological studies.

New Jurassic mammaliaform sheds light on early evolution of mammal-like hyoid bones

A Jurassic fossil shows that early premammalian ancestors possessed hyoids similar to those seen in mammals today, and a new Jurassic docodontan mammaliaform found in China that is preserved with the hyoid bones is reported.

Reptile-like physiology in Early Jurassic stem-mammals

Synchrotron X-ray imaging of incremental tooth cementum shows two Early Jurassic stem-mammals, Morganucodon and Kuehneotherium, had lifespans considerably longer than comparably sized living mammals, but similar to reptile-like physiology, and maximum metabolic rates increased evolutionarily before basal rates.



Mammal disparity decreases during the Cretaceous angiosperm radiation

It is concluded that during the mid-Cretaceous, the period of rapid angiosperm radiation, mammals experienced both a decrease in morphological disparity and a functional shift in dietary morphology that were probably related to changing ecosystems.

In quest for a phylogeny of Mesozoic mammals

A phylogeny of all major groups of Mesozoic mammals based on phylogenetic analyses of 46 taxa and 275 osteological and dental characters, using parsimony methods is proposed, suggesting that the “obtuse−angle symmetrodonts” are paraphyletic, and that they lack reliable and unambiguous synapomorphies.

Impacts of the Cretaceous Terrestrial Revolution and KPg Extinction on Mammal Diversification

Molecular phylogenetic analysis, calibrated with fossils, resolves the time frame of the mammalian radiation and diversification analyses suggest important roles for the Cretaceous Terrestrial Revolution and KPg mass extinction in opening up ecospace that promoted interordinal and intraordinal diversification, respectively.

The Placental Mammal Ancestor and the Post–K-Pg Radiation of Placentals

A phylogenetic tree shows that crown clade Placentalia and placental orders originated after the K-Pg boundary, but phenomic signals overturn molecular signals to show Sundatheria (Dermoptera + Scandentia) as the sister taxon of Primates, a close link between Proboscidea and Sirenia (sea cows), and the monophyly of echolocating Chiroptera (bats).

A Functional morphospace for the skull of labrid fishes: patterns of diversity in a complex biomechanical system

It is hypothesized that the functional and ecological diversity of labrids is due in part to a history of decoupled evolution of major components of the feeding system as well as among the muscular and skeletal elements of each component.

Quantitative analysis of dental microwear in threespine stickleback: a new approach to analysis of trophic ecology in aquatic vertebrates.

It is demonstrated here that quantitative analysis of dental microwear, a technique previously applied only to mammals, provides a reliable guide to the dietary preferences of stickleback, allowing the role of trophic ecology, niche partitioning and competition over evolutionary time-scales to be investigated for the first time.

Ecomorphological analysis of trophic niche partitioning in a tropical savannah bat community

Comparisons of three species with highly specialized feeding habits with the rest of the species in the community indicate that specialization into these niches comes at the expense of bite performance and, hence, may result in a reduction of the trophic niche breadth.

Ancient Smaller Vertebrates. (Book Reviews: In the Shadow of the Dinosaurs. Early Mesozoic Tetrapods.)

The fossil record of Late Triassic and Jurassic amphibians: fossil record and phylogeny, with special emphasis on the Lepidosauromorpha, and faunal Assemblages and Faunal Change are presented.

Transformation and diversification in early mammal evolution

Newly discovered fossils show that evolution of such key characters as the middle ear and the tribosphenic teeth is far more labile among Mesozoic mammals.

A Swimming Mammaliaform from the Middle Jurassic and Ecomorphological Diversification of Early Mammals

This fossil demonstrates that some mammaliaforms, or proximal relatives to modern mammals, developed diverse locomotory and feeding adaptations and were ecomorphologically different from the majority of generalized small terrestrial Mesozoic mammalian insectivores.