Blair W. McPhee's research while affiliated with University of the Witwatersrand and other places

Publications (22)

Article
The Massospondylus Assemblage Zone is the youngest tetrapod biozone in the Karoo Basin (upper Stormberg Group, Karoo Supergroup) and records one of the oldest dinosaur dominated ecosystems in southern Gondwana. Recent qualitative and quantitative investigations into the biostratigraphy of the lower and upper Elliot formations (lEF, uEF) and Clarens...
Article
The Scalenodontoides Assemblage Zone (SAZ) is the oldest fossil tetrapod biozone of the Stormberg Group (Karoo Supergroup) and preserves the oldest dinosaur bearing deposits in the Karoo Basin. The SAZ represents a revision of the ‘Euskelosaurus’ Range Zone, whose taxonomic basis has been undermined because ‘Euskelosaurus’ is well demonstrated to b...
Article
Full-text available
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 sauro...
Data
Majority-rule consensus of the MPTs resulting from the phylogenetic analysis. (EMF)
Article
Full-text available
Sauropodomorphs are the most abundant and diverse clade of Triassic dinosaurs, but the taxonomy of their earliest (Carnian) representatives is still poorly understood. One such taxon is Pampadromaeus barberenai, represented by a nearly complete disarticulated skeleton recovered from the upper part of the Santa Maria Formation of Rio Grande do Sul,...
Data
List of 413 characters employed in the phylogenetic analysis. (DOCX)
Article
Sauropod dinosaurs were dominant, bulk-browsing herbivores for 130 million years of the Mesozoic, attaining gigantic body masses in excess of 60 metric tons [1, 2]. A columnar-limbed, quadrupedal posture enabled these giant body sizes [3], but the nature of the transition from bipedal sauropodomorph ancestors to derived quadrupeds remains contentio...
Article
We present the complete osteology of the putative basal sauropod Pulanesaura eocollum. Current phylogenetic hypotheses suggest that Pulanesaura is the sister taxon of Vulcanodon + other sauropods, a position supported primarily by derived features of its axial skeleton and forelimb. A question of nontrivial importance is therefore the relative posi...
Article
Full-text available
A palaeosurface with one megatheropod trackway and several theropod tracks and trackways from the Lower Jurassic upper Elliot Formation (Stormberg Group, Karoo Supergroup) in western Lesotho is described. The majority of the theropod tracks are referable to either Eubrontes or Kayentapus based on their morphological characteristics. The larger mega...
Article
Full-text available
The latest Triassic is notable for coinciding with the dramatic decline of many previously dominant groups, followed by the rapid radiation of Dinosauria in the Early Jurassic. Among the most common terrestrial vertebrates from this time, sauropodomorph dinosaurs provide an important insight into the changing dynamics of the biota across the Triass...
Article
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The Early Jurassic of China has long been recognized for its diverse array of sauropodomorph dinosaurs. However, the contribution of this record to our understanding of early sauropod evolution is complicated by a dearth of information on important transitional taxa. We present a revision of the poorly known taxon Sanpasaurus yaoi Young, 1944 from...
Chapter
The nonmarine Permo-Jurassic deposits of the Karoo Supergroup of South Africa have long been a world standard for tetrapod biostratigraphy. Recent and ongoing research is revising the palaeoflora and palaeofauna of these sedimentary strata with an unprecedented level of stratigraphic precision. This work has shown that: Permian palynomorphs are use...
Article
It has generally been held that the locomotory habits of sauropodomorph dinosaurs moved in a relatively linear evolutionary progression from bipedal through “semi-bipedal” to the fully quadrupedal gait of Sauropoda. However, there is now a growing appreciation of the range of locomotory strategies practiced amongst contemporaneous taxa of the lates...
Article
Full-text available
The early evolution of sauropod dinosaurs remains poorly understood, with a paucity of unequivocal sauropod taxa known from the first twenty million years of the Jurassic. Recently, the Early Jurassic of South Africa has yielded an assemblage of dental and post-cranial remains displaying a more apomorphic character suite than any other similarly ag...
Article
Full-text available
The Late Triassic-Early Jurassic Elliot Formation of South Africa is one of the most important geological formations worldwide for understanding the early evolution of sauropodomorph dinosaurs. However, many of the taxa currently recognized as valid within its lower strata remain either poorly understood, vaguely diagnosed, or both. The recent disc...
Article
Full-text available
We present a comprehensive description and phylogenetic analysis of the important transitional sauropodomorph Antetonitrus ingenipes. New information sheds light on the stepwise acquisition of sauropod-like traits just prior to the Triassic/Jurassic boundary. Although the forelimb of Antetonitrus and other closely related sauropodomorph taxa retain...

Citations

... The single CA-TIMS age is from the upper third of the lower Elliot Formation and thus implies strata above this horizon are younger than 208-209 Ma . This suggests some portion of the lower or middle part of the lower Elliot is best correlated with the upper Los Colorados vertebrate assemblage (Fig. 3a), which is reasonable given that both are dominated by sauropodomorph dinosaurs in terms of richness and abundance (e.g., Marsicano et al., 2016;Bordy et al., 2020;Viglietti et al., 2020), and in several cases there are close phylogenetic relationships between taxa from each unit (e.g., Riojasaurus and Eucnemesaurus, Lessemsaurus and Meroktenos; see Pol et al., 2021a). The confirmation of an Early Jurassic age for the upper Elliot Formation, with its diverse tetrapod assemblage including ornithischian and theropod dinosaurs, compares well with the earliest Jurassic bonebed of the La Quinta Formation (Venezuela), which also preserves those clades. ...
... However, new phylogenetic analyses have proposed that two other taxa, Lesothosaurus and Laquintasaura, might be early members of Thyreophora (e.g., Butler et al., 2008;Boyd, 2015;Baron et al., 2017a;Raven and Maidment, 2017;Maidment et al., 2020), although these views are contentious and alternative relationships for these taxa have been posited (e.g., Dieudonné et al., 2021;Barta and Norell, 2021;Norman, 2021). If Lesothosaurus and Laquintasaura are thyreophorans, however, this broadens the palaeogeographic distribution of the clade to Gondwana in the earliest Jurassic, with Laquintasaura from the Hettangian of Venezuela and Lesothosaurus from the Sinemurian of southern Africa (Viglietti et al., 2020), implying that the group might have originated in Gondwana and dispersed to Laurasia (Boyd, 2015;Raven et al., 2019;Maidment et al., 2020). If it is of the Early Jurassic age, the material from the Kota Formation would support an early Gondwanan distribution also (Nath et al., 2002;Galton, 2019). ...
... The main Karoo Basin of southern Africa (Figure 1), which encapsulates ∼120 million years of geological history from the Late Carboniferous to Early Jurassic, preserves one of the world's most extensive continental successions, i.e., the Karoo Supergroup (e.g., Rubidge et al., 2016;Bordy et al., 2020). The Triassic-Jurassic upper Stormberg Group (i.e., Elliot and Clarens formations) preserves a rich, diverse body and trace fossil assemblage, making it an ideal stratigraphic succession for unraveling early dinosaur evolution in southwestern Gondwana. ...
... Martínez et al. 2012b;Cabreira et al. 2016;Pretto et al. 2017;Müller et al. 2018a), and intermediate arrangements have also been proposed. For example, a clade including part of the Carnian sauropodomorph diversity was termed Saturnaliidae by Langer et al. (2019), translated from Saturnaliinae Ezcurra (2010), whereas its sister clade was named Bagualosauria. The latter clade includes a single Carnian taxon, the name-bearing Ba. agudoensis . ...
... It is well established that maximum dinosaur body size had a general increasing trend throughout the Mesozoic (e.g., Benson et al., 2014;McPhee et al., 2018;Lallensack et al., 2019). The end-Triassic mass extinction events and Triassic-Jurassic boundary marked pivotal periods in dinosaur evolution and radiation, but unfortunately, an incomplete fossil record obscures the early evolution of large bodied theropod dinosaurs (Brusatte et al., 2010). ...
... Open Sci. 9: 211356 19 Thecodontosaurus, although it becomes reduced or absent in derived sauropodiforms and sauropods (figure 7; [91,[94][95][96][97]). As such, the origin of M. brachialis has been inferred on the cuboid fossa in early sauropodomorphs such as Saturnalia and Plateosaurus [26,36], although the alternative humeral shaft origin has been proposed for Mussaurus [25]. ...
... Consequently, the global ichnological record has proven to be an invaluable complement to the osteological record for unraveling dinosaur evolutionary history. To date, the early history of dinosaurs is still poorly understood, with controversy surrounding the timing of their origins during the Triassic (e.g., Marsicano et al., 2007;Brusatte et al., 2008Brusatte et al., , 2010Brusatte et al., , 2011Baron et al., 2017;Langer et al., 2017) and the cause of their ascent and dominance later in the Mesozoic (e.g., Olsen et al., 2002Olsen et al., , 2010Padian, 2012). The Triassic-Jurassic boundary has often been considered to mark a crucial period in dinosaur history, evidenced by significant diversification, population and body size increases in the Early Jurassic, possibly linked to a recovery period following the end-Triassic mass extinction events (see "diminished competitor capacity" concept, e.g., Olsen et al., 2002). ...
... Although the exact placement of the Triassic-Jurassic boundary within the upper Stormberg Group is unknown, recent radiometric dating suggests a Norian-Rhaetian age for the lower Elliot Formation (lEF), a Hettangian to Sinemurian age for the upper Elliot Formation (uEF) and a Sinemurian to Pliensbachian age for the Clarens Formation (Figure 1; Bordy et al., 2020). Upper Stormberg Group vertebrate tracks, attributed to dinosaurs, have been known since in the 1800s (Dieterlen, 1885) and formally documented since the early 1900s (Dornan, 1908) with a boom in systematic documentation in the second half of the 20th century and post-2015 (e.g., Ellenberger, 1955Ellenberger, , 1970Ellenberger, , 1972Ellenberger, , 1974Ellenberger and Ellenberger, 1956, 1958, 1960Ellenberger et al., 1963;Ambrose, 2003;Raath and Yates, 2005;Smith et al., 2009;Sciscio et al., 2016Sciscio et al., , 2017Abrahams et al., 2017Abrahams et al., , 2020aBordy et al., 2017;Rampersadh et al., 2018;Bordy, 2021). Like many other early Mesozoic vertebrate ichnoassemblages attributed to dinosaurs (e.g., Petti et al., 2008;Belvedere et al., 2010;Moreno et al., 2012;Lockley et al., 2013;Läng et al., 2013;Pérez-Lorente, 2015;D'Orazi Porchetti et al., 2016;Xing et al., 2020), the upper Stormberg Group dinosaur track record comprises tracks primarily assigned to Kayentapus, Grallator, Anchisauripus, and Eubrontes. ...
... The Norian is traditionally considered a key-period for dinosaur evolution, when the group attained higher faunal dominance (McPhee et al., 2017;, larger sizes (Benson et al., 2014;Apaldetti et al., 2018;Pradelli et al., 2022), greater disparity (Brusatte et al., 2008;Apaldetti et al., 2021), and a broader geographical distribution (Kent and Clemmensen 2021), although some of these patterns are clearly clade-and region-specific (Whiteside et al., 2015). ...