Reassessment of Unaysaurus tolentinoi (Dinosauria: Sauropodomorpha) from the Late Triassic (early Norian) of Brazil, with a consideration of the evidence for monophyly within non-sauropodan sauropodomorphs

  title={Reassessment of Unaysaurus tolentinoi (Dinosauria: Sauropodomorpha) from the Late Triassic (early Norian) of Brazil, with a consideration of the evidence for monophyly within non-sauropodan sauropodomorphs},
  author={Blair Wayne McPhee and Jonathas S. Bittencourt and Max Cardoso Langer and Cecilia Apaldetti and {\'A}tila A. S. Da Rosa},
  journal={Journal of Systematic Palaeontology},
  pages={259 - 293}
We present a systematic revision of the ‘prosauropod’ dinosaur Unaysaurus tolentinoi. Past phylogenetic treatments of this taxon have presented it as a key constituent of the low-diversity Plateosauridae. This clade, along with Massospondylidae, is currently regarded as a relatively non-controversial example of monophyly within non-sauropodan sauropodomorphs – an otherwise pectinate grade of animals from which the apically nested Sauropoda is derived. The inclusion of Unaysaurus within… 

Craniomandibular osteology of Macrocollum itaquii (Dinosauria: Sauropodomorpha) from the Late Triassic of southern Brazil

  • R. Müller
  • Biology, Environmental Science
    Journal of Systematic Palaeontology
  • 2019
A detailed description of the craniomandibular anatomy of M. itaquii is presented, based on the holotype, a paratype and a newly referred specimen, to elucidate the transition from slender basal sauropodomorphs to more robust derived members within this group.

Osteological Redescription of the Late Triassic Sauropodomorph Dinosaur Thecodontosaurus antiquus Based on New Material from Tytherington, Southwestern England

ABSTRACT Thecodontosaurus antiquus is a basal sauropodomorph from the Rhaetian locality of Durdham Down in Bristol, U.K. Sauropodomorph material putatively assigned to this species was found at the

Ontogenetic changes in the postcranial skeleton of Mussaurus patagonicus (Dinosauria, Sauropodomorpha) and their impact on the phylogenetic relationships of early sauropodomorphs

  • A. OteroD. Pol
  • Biology, Environmental Science
    Journal of Systematic Palaeontology
  • 2021
The osteology of the postcranial skeleton of immature specimens of Mussaurus is presented, highlighting the main anatomical changes that occurred during its ontogeny and supporting the hypothesis of paedomorphic evolution in certain regions of the skeleton.

Issi saaneq gen. et sp. nov.—A New Sauropodomorph Dinosaur from the Late Triassic (Norian) of Jameson Land, Central East Greenland

The Late Triassic (Norian) outcrops of the Malmros Klint Formation, Jameson Land (Greenland) have yielded numerous specimens of non-sauropod sauropodomorphs. Relevant fossils were briefly reported in

A new massopodan sauropodomorph from Trossingen Formation (Germany) hidden as ‘ Plateosaurus’ for 100 years in the historical Tübingen collection

A framework to compare phylogenetic signals with morphological and histological data is provided to help in the species delineation of Plateosaurus, and support is found to refer the historic specimen ‘GPIT IV’ as a new genus and a new species.

Walking with early dinosaurs: appendicular myology of the Late Triassic sauropodomorph Thecodontosaurus antiquus

This reconstruction helps to elucidate the timing of important modifications of the appendicular musculature in the evolution of sauropodomorphs which facilitated the transition to quadrupedalism and contributed to their evolutionary success.

New skulls of the basal sauropodomorph Plateosaurus trossingensis from Frick, Switzerland: is there more than one species?

New skull material from Frick is described including eight complete and six partial skulls, more than doubling the number of known skulls of P. trossingensis and includes the first known juvenile skulls of Plateosaurus, allowing for detecting ontogenetic changes.

The braincase, brain and palaeobiology of the basal sauropodomorph dinosaur Thecodontosaurus antiquus

The braincase osteology and neuroanatomy of Thecodontosaurus are redescribed and the endocranial reconstruction is reconstructed, revealing important aspects of the palaeobiology of The codontosaurus, supporting a bipedal stance and cursorial habits, with adaptations to retain a steady head and gaze while moving.

Disentangling biological variability and taphonomy: shape analysis of the limb long bones of the sauropodomorph dinosaur Plateosaurus

This work investigates quantitatively the morphological variation of Plateosaurus occurring at the genus level by studying the shape variation of a sample of limb long bones by means of 3D geometric morphometrics.



A new species of the primitive dinosaur Thecodontosaurus (Saurischia: Sauropodomorpha) and its implications for the systematics of early dinosaurs

Synopsis Juvenile sauropodomorph specimens from a Late Triassic/Early Jurassic fissure fill in Pant‐y‐ffynnon Quarry, South Wales are redescribed and named as a new species, Thecodontosaurus caducus.

A New Sauropodomorph Dinosaur from the Early Jurassic of Patagonia and the Origin and Evolution of the Sauropod-type Sacrum

The dental and postcranial anatomy of Leonerasaurus supports its close affinities with basal sauropods, and shows that the characteristic sauropod body plan evolved gradually, with a step-wise pattern of character appearance.

New stem-sauropodomorph (Dinosauria, Saurischia) from the Triassic of Brazil

A new Late Triassic dinosaur from the Santa Maria Formation of Rio Grande do Sul, southern Brazil is reported, showing dinosaur plesiomorphies together with some neotheropod traits.

A Basal Sauropodomorph (Dinosauria: Saurischia) from the Ischigualasto Formation (Triassic, Carnian) and the Early Evolution of Sauropodomorpha

The presence of Panphagia at the base of the early Carnian Ischigualasto Formation suggests an earlier origin of Sauropodomorpha during the Middle Triassic, and is regarded as the most basal sauropodomorph.

A phylogenetic analysis of basal sauropodomorph relationships: Implications for the origin of sauropod dinosaurs2

The most parsimonious trees suggest that Efraasia, Mussaurus, Thecodontosaurus and Saturnalia are increasingly more distant sister-taxa to the remaining sauropodomorphs, while character mapping indicates several apomorphic features that support the monophyly of a plateosaurian clade or subgroups within it.

A new basal sauropod from the pre-Toarcian Jurassic of South Africa: evidence of niche-partitioning at the sauropodomorph–sauropod boundary?

Key changes in the dentition, axial skeleton and forelimb of this new species suggest a genuine functional distinction occurring at the sauropodiform-sauropod boundary, which may partially explain the rarity of true sauropods in the basal rocks of the Jurassic.

A new early dinosaur (Sauropodomorpha) from the Caturrita Formation (Late Triassic), Paran Basin, Brazil

Unaysaurus represents the first prosauropod grade dinosaur from Brazil and a preliminary phylogenetic analysis indicates it to be closely related to the European Plateosaurus (Plateosauridae).

Adeopapposaurus mognai, gen. et sp. nov. (Dinosauria: Sauropodomorpha), with Comments on Adaptations of Basal Sauropodomorpha

The specimens described here reveal numerous herbivorous adaptations, including the presence of a highly vascularized bony plate in the premaxilla and dentary, which indicates that Adeopapposaurus mognai had a horny beak.

A new basal sauropodiform from South Africa and the phylogenetic relationships of basal sauropodomorphs

Sefapanosaurus, together with other transitional sauropodomorphs reported during the last decade, highlights the importance of Gondwanan taxa for understanding the palaeobiodiversity, global distribution, and macroevolutionary changes in the group related to the rise of sauropods.

A revision of the problematic sauropodomorph dinosaurs from Manchester, Connecticut and the status of Anchisaurus Marsh

A revised cladistic analysis continues to find support for Anchisaurus as a relatively derived basal sauropodomorph that lies outside of the clade Melanorosaurus + Sauropoda but is more closely related to it than to ‘core prosauropods’ such as Plateosaurus and Massospondylus.