Are the dinosauromorph femora from the Upper Triassic of Hayden Quarry (New Mexico) three stages in a growth series of a single taxon?

Müller, Rodrigo Temp

doi:10.1590/0001-3765201720160583

Cited by 6 publications

(5 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Galton, 1982, 2010; Brochu, 1992, 1996; Martin, 1994; Curry, 1999; Tumarkin‐Deratzian et al ., 2006, 2007; Griffin & Nesbitt, 2016 a ; Cotts et al ., 2017), especially among early bird‐line archosaurs (e.g. Raath, 1990; Tykoski, 1998, 2005; Nesbitt et al ., 2009 b ; Maidment & Barrett, 2012; Piechowski et al ., 2014; Griffin & Nesbitt, 2016 a , b ; Müller, 2017; Griffin et al ., 2019; Müller et al ., 2019; Nesbitt, Langer & Ezcurra, 2020), although bone scar ‘robustness’ has been used among other reptile groups as well [e.g. sauropterygians (Wiffen et al ., 1995; Knutsen et al ., 2012)].…”

Section: Methods Of Assessing Maturitymentioning

confidence: 99%

Assessing ontogenetic maturity in extinct saurian reptiles

et al. 2020

View full text Add to dashboard Cite

Morphology forms the most fundamental level of data in vertebrate palaeontology because it is through interpretations of morphology that taxa are identified, creating the basis for broad evolutionary and palaeobiological hypotheses. Assessing maturity is one of the most basic aspects of morphological interpretation and provides the means to study the evolution of ontogenetic changes, population structure and palaeoecology, life‐history strategies, and heterochrony along evolutionary lineages that would otherwise be lost to time. Saurian reptiles (the least‐inclusive clade containing Lepidosauria and Archosauria) have remained an incredibly diverse, numerous, and disparate clade through their ~260‐million‐year history. Because of the great disparity in this group, assessing maturity of saurian reptiles is difficult, fraught with methodological and terminological ambiguity. We compiled a novel database of literature, assembling >900 individual instances of saurian maturity assessment, to examine critically how saurian maturity has been diagnosed. We review the often inexact and inconsistent terminology used in saurian maturity assessment (e.g. ‘juvenile’, ‘mature’) and provide routes for better clarity and cross‐study coherence. We describe the various methods that have been used to assess maturity in every major saurian group, integrating data from both extant and extinct taxa to give a full account of the current state of the field and providing method‐specific pitfalls, best practices, and fruitful directions for future research. We recommend that a new standard subsection, ‘Ontogenetic Assessment’, be added to the Systematic Palaeontology portions of descriptive studies to provide explicit ontogenetic diagnoses with clear criteria. Because the utility of different ontogenetic criteria is highly subclade dependent among saurians, even for widely used methods (e.g. neurocentral suture fusion), we recommend that phylogenetic context, preferably in the form of a phylogenetic bracket, be used to justify the use of a maturity assessment method. Different methods should be used in conjunction as independent lines of evidence when assessing maturity, instead of an ontogenetic diagnosis resting entirely on a single criterion, which is common in the literature. Critically, there is a need for data from extant taxa with well‐represented growth series to be integrated with the fossil record to ground maturity assessments of extinct taxa in well‐constrained, empirically tested methods.

show abstract

Section: Methods Of Assessing Maturitymentioning

confidence: 99%

Assessing ontogenetic maturity in extinct saurian reptiles

et al. 2020

View full text Add to dashboard Cite

show abstract

“…It should be noted that there is still a basic gap in the basal coelurosaurs, making their diversification processes unclear. Establishing ontogenetic state is quite hard in fossils overall, including theropod dinosaurs 61 , for all based on incomplete material. However, based on osteohistology, the animal was still growing at the time of its death.…”

Section: Discussionmentioning

confidence: 99%

“…Establishing ontogenetic state is quite hard in fossils overall, including theropod dinosaurs 61 , for all based on incomplete material. However, based on osteohistology, the animal was still growing at the time of its death.…”

Section: Discussionmentioning

confidence: 99%

The first theropod dinosaur (Coelurosauria, Theropoda) from the base of the Romualdo Formation (Albian), Araripe Basin, Northeast Brazil

Sayão

Saraiva

Brum

et al. 2020

Sci Rep

View full text Add to dashboard Cite

The Romualdo Formation (Araripe Basin) is worldwide known for the large number of well-preserved fossils but the dinosaur record is rather scarce. Here we describe a new coelurosaur, which is the first tetrapod recovered from the basal layers of this stratigraphic unit that consist of dark shales. Aratasaurus museunacionali gen. et sp. nov. is known by an incomplete but articulated right hind limb with the distal portion of the femur, proximal half of tibia and incomplete pes. The new species differs from other coelurosaurs by a medial fossa in the tibia and digits II, III and IV being symmetric. The phylogenetic analysis recovered Aratasaurus museunacionali closely related to Zuolong salleei, forming a basal coelurosaur lineage. The paleohistology indicate that the specimen is a juvenile, with an estimated body length around 3.12 m. The new taxon represents the first occurrence of basal coelurosaurians in the Araripe Basin and suggests a widespread distribution of this group during the Lower Cretaceous. The dinosaur record in Brazil is still quite meager compared to the potential of the country 1,2. So far, most specimens were recovered from the Bauru Group, including non-avian theropods 3,4,5,6,7. The latter are less numerous in these deposits than other reptiles 8 , leading to several discussions, including niche partitioning 7. The limited amount of theropod material is not exclusive of Brazil 9. Among the regions where such reptiles are found in the country is the Araripe Basin 10. This tectonic structure is worldwide known for the well preserved and diverse fossil biota 11,12,13,14. The most fossiliferous units are the Lower Cretaceous Crato and Romualdo formations, comprising the majority of fossil vertebrates of this basin 14. As has been reported several times, the most common tetrapod in both units are pterosaurs 15 , while others tend to be rare 16,17,18. Until now all non-avian dinosaur from the Araripe Basin came exclusively from the Romualdo Formation and are represented by the spinosaurids Irritator challengeri 19 and Angaturama limai 1 and the non-avian coelurosaurs Santanaraptor placidus 20,21 and Mirischia assymetrica 22. All were preserved in the level of carbonate concretions from the upper portion of this stratigraphic unit 14,23,24. Here we describe a new theropod dinosaur from the Romualdo Formation that was collected in the lower section. The fossil is preserved in a slab of dark shale, housed at the Museu de Paleontologia Plácido Cidade

show abstract

“…Specifically, D. romeri lacks an ilium with a convex ventral acetabular margin (= “imperforate” acetabulum, character 273–0, Nesbitt, 2011; GR 1041), a fibular condyle of the tibia that is level with the medial condyle at its caudal border (character 201–1 from Cabreira et al, 2016; character from Langer & Benton, 2006), and a posterior groove present on the astragalus (character 217–1 from Cabreira et al, 2016; character from Nesbitt, 2011). In addition, D. romeri has been independently supported as a unique taxon of non-dinosaurian dinosauromorph based on the large number of differences in femoral characters between D. romeri and Tawa hallae compared to ontogenetic series of other early dinosauromorphs (Müller, 2017). Thus, all current evidence strongly supports the original division of the two taxa and we concur with Müller (2017) in considering D. romeri to be a non-dinosaurian dinosauromorph.…”

Section: Methodsmentioning

confidence: 99%

“…In addition, D. romeri has been independently supported as a unique taxon of non-dinosaurian dinosauromorph based on the large number of differences in femoral characters between D. romeri and Tawa hallae compared to ontogenetic series of other early dinosauromorphs (Müller, 2017). Thus, all current evidence strongly supports the original division of the two taxa and we concur with Müller (2017) in considering D. romeri to be a non-dinosaurian dinosauromorph. Nonetheless, our examination here of the gross morphological and histological ontogeny of D. romeri provides further evidence to test Bennett’s (2015) hypothesis.…”

Section: Methodsmentioning

confidence: 99%

Integrating gross morphology and bone histology to assess skeletal maturity in early dinosauromorphs: new insights fromDromomeron(Archosauria: Dinosauromorpha)

Griffin

Bano

Turner

et al. 2019

PeerJ

View full text Add to dashboard Cite

Understanding growth patterns is central to properly interpreting paleobiological signals in tetrapods, but assessing skeletal maturity in some extinct clades may be difficult when growth patterns are poorly constrained by a lack of ontogenetic series. To overcome this difficulty in assessing the maturity of extinct archosaurian reptiles—crocodylians, birds and their extinct relatives—many studies employ bone histology to observe indicators of the developmental stage reached by a given individual. However, the relationship between gross morphological and histological indicators of maturity has not been examined in most archosaurian groups. In this study, we examined the gross morphology of a hypothesized growth series of Dromomeron romeri femora (96.6–144.4 mm long), the first series of a non-dinosauriform dinosauromorph available for such a study. We also histologically sampled several individuals in this growth series. Previous studies reported that D. romeri lacks well-developed rugose muscle scars that appear during ontogeny in closely related dinosauromorph taxa, so integrating gross morphology and histological signal is needed to determine reliable maturity indicators for early bird-line archosaurs. We found that, although there are small, linear scars indicating muscle attachment sites across the femur, the only rugose muscle scar that appears during ontogeny is the attachment of the M. caudofemoralis longus, and only in the largest-sampled individual. This individual is also the only femur with histological indicators that asymptotic size had been reached, although smaller individuals possess some signal of decreasing growth rates (e.g., decreasing vascular density). The overall femoral bone histology of D. romeri is similar to that of other early bird-line archosaurs (e.g., woven-bone tissue, moderately to well-vascularized, longitudinal vascular canals). All these data indicate that the lack of well-developed femoral scars is autapomorphic for this species, not simply an indication of skeletal immaturity. We found no evidence of the high intraspecific variation present in early dinosaurs and other dinosauriforms, but a limited sample size of other early bird-line archosaur growth series make this tentative. The evolutionary history and phylogenetic signal of gross morphological features must be considered when assessing maturity in extinct archosaurs and their close relatives, and in some groups corroboration with bone histology or with better-known morphological characters is necessary.

show abstract

Are the dinosauromorph femora from the Upper Triassic of Hayden Quarry (New Mexico) three stages in a growth series of a single taxon?

Cited by 6 publications

References 9 publications

Assessing ontogenetic maturity in extinct saurian reptiles

Assessing ontogenetic maturity in extinct saurian reptiles

The first theropod dinosaur (Coelurosauria, Theropoda) from the base of the Romualdo Formation (Albian), Araripe Basin, Northeast Brazil

Integrating gross morphology and bone histology to assess skeletal maturity in early dinosauromorphs: new insights fromDromomeron(Archosauria: Dinosauromorpha)

Contact Info

Product

Resources

About