The largest thalattosuchian (Crocodylomorpha) supports teleosaurid survival across the Jurassic-Cretaceous boundary

Fanti, Federico; Miyashita, Tetsuto; Cantelli, Luigi; Mnasri, Fawsi; Dridi, Jihed; Contessi, Michela; Cau, Andrea

doi:10.1016/j.cretres.2015.11.011

Cited by 48 publications

(84 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The alveoli are comparable in size to those of the giant marine thalattosuchian Machimosaurus rex (Fanti et al, 2016). The large skull dimensions (and likely body size, too) reached by R. sakalavae , together with the peculiar feeding adaptations indicated by the dental and cranial features, suggest that this taxon was a highly specialized predatory crocodyliform of terrestrial habits, that could compete and occupy the ecological niches of theropod dinosaurs.…”

Section: Discussion and Comparisonsmentioning

confidence: 92%

Razanandrongobe sakalavae,a gigantic mesoeucrocodylian from the Middle Jurassic of Madagascar, is the oldest known notosuchian

Sasso¹,

Pasini²,

Fleury³

et al. 2017

PeerJ

View full text Add to dashboard Cite

Razanandrongobe sakalavae Maganuco, Dal Sasso & Pasini, 2006 is a large predatory archosaur from the Middle Jurassic (Bathonian) of the Mahajanga Basin, NW Madagascar. It was diagnosed on the basis of teeth and a fragmentary maxilla, but its affinities were uncertain. Here we describe new cranial remains (above all, an almost complete right premaxilla and a caudally incomplete left dentary) that greatly improve our knowledge on this enigmatic species and reveal its anatomy to be crocodylomorph. The right premaxilla indicates that the rostrum was deep, wide, and not pointed; it bears five teeth that are sub-vertical and just slightly curved lingually; the mesial teeth are U-shaped in cross-section and have serrated carinae on the lingual side; the aperturae nasi osseae (external bony nares) are confluent and face rostrally; and there is no lateral groove at the premaxillomaxillary suture for reception of a hypertrophied lower caniniform tooth. The preserved portion of the left dentary has an edentulous tip and bears eight large mandibular teeth of which the mesial (1–3) are the largest, but none is a hypertrophied caniniform tooth; the mandibular (dentary) symphysis extends caudally to the level of the third tooth; the splenial is not preserved, but its sutural marks on the dentary indicate that it contributed to the mandibular symphysis for at least 20% of the symphyseal length in dorsal aspect. On the basis of this new data, some previously uncertain features of the holotype maxilla—such as the margin of the suborbital fenestra, the contact surfaces for the palatine, the ectopterygoid, and the jugal—are now apparent. Testing of the phylogenetic position of the species within Crocodylomorpha indicates that R. sakalavae is a mesoeucrocodylian. It also represents one of the earliest events of exacerbated increase in body size along the evolutionary history of the group. In addition, it is by far the oldest notosuchian. A cranial reconstruction of this gigantic predator is also attempted here. The very robust jaw bones of R. sakalavae, coupled with its peculiar dentition, strongly suggest a diet that included hard tissue such as bone and tendon.

show abstract

Section: Discussion and Comparisonsmentioning

confidence: 92%

Razanandrongobe sakalavae,a gigantic mesoeucrocodylian from the Middle Jurassic of Madagascar, is the oldest known notosuchian

Sasso¹,

Pasini²,

Fleury³

et al. 2017

PeerJ

View full text Add to dashboard Cite

show abstract

“…; Fanti et al . ). Many derived macropredatory cetaceans, including modern forms, have simple conical crowns and uniform dentition as well (e.g.…”

Section: Discussionmentioning

confidence: 97%

Increased pliosaurid dental disparity across the Jurassic–Cretaceous transition

et al. 2018

View full text Add to dashboard Cite

Pliosaurid marine reptiles played important roles in marine food chains from the Middle Jurassic to the middle Cretaceous, frequently as apex predators. The evolution of pliosaurids during the later parts of the Early Cretaceous has recently been illuminated by discoveries from Russia (Hauterivian) and Colombia (Barremian). However, knowledge of pliosaurids representing the Jurassic–Cretaceous transition (late Tithonian – Valanginian), is still largely incomplete, especially during the earliest Cretaceous. As such, the effect on pliosaurids of hypothesized faunal turnover during the Jurassic–Cretaceous boundary interval is poorly understood. We report pliosaurid teeth from the upper Volgian (Tithonian, Upper Jurassic) of the Kheta river basin (Eastern Siberia, Russia), to the Berriasian and Valanginian (Lower Cretaceous) of the Volga region (European Russia). These assemblages have yielded a series of distinct tooth morphotypes, including the first reports of conical‐toothed pliosaurids from the latest Jurassic and earliest Cretaceous. This challenges the hypothesis that only one lineage of pliosaurids crossed the Jurassic–Cretaceous boundary. It appears that conical‐toothed pliosaurids co‐existed with their trihedral‐toothed relatives for at least 25 million years during the latest Jurassic and earliest Cretaceous. In fact, our quantitative analyses indicate that pliosaurids reached their maximal dental disparity during this interval, showing little evidence of turnover associated with the Jurassic–Cretaceous transition. Instead, disparity decreased later in the Early Cretaceous, with the disappearance of trihedral‐toothed forms in the Barremian.

show abstract

“…[31,71,72] and the teleosaurids [45,55,73]. Regarding the thalattosuchians that adopted a pelagic lifestyle involving long-term apneas (Metriorhynchidae; [44][45][46]), the loss of the dermal shield must have negatively impacted their performance in bone acidosis buffering. Nevertheless, other pathways can buffer acidosis via the involvement of soft tissues [74].…”

Section: Discussion (A) Pseudosuchian Osteoderm Vascularization: Histmentioning

confidence: 99%

“…The taxa were categorized based on two different lifestyles: terrestrial and semi-aquatic (table 1b). We decided not to distinguish the marine animals from the freshwater semi-aquatic forms as they have a similar amphibious ambush predator lifestyle [43,44]. The pelagic marine forms from the Jurassic (the metryorhinchids) [45,46] had completely lost the osteoderm shield and are therefore not suitable for this study (this aspect is discussed below).…”

Section: Materials and Methods (A) Sampling Strategymentioning

confidence: 99%

The evolution of dermal shield vascularization in Testudinata and Pseudosuchia: phylogenetic constraints versus ecophysiological adaptations

Clarac

Scheyer

Desojo

et al. 2020

Phil. Trans. R. Soc. B

View full text Add to dashboard Cite

Studies on living turtles have demonstrated that shells are involved in the resistance to hypoxia during apnea via bone acidosis buffering; a process which is complemented with cutaneous respiration, transpharyngeal and cloacal gas exchanges in the soft-shell turtles. Bone acidosis buffering during apnea has also been identified in crocodylian osteoderms, which are also known to employ heat transfer when basking. Although diverse, many of these functions rely on one common trait: the vascularization of the dermal shield. Here, we test whether the above ecophysiological functions played an adaptive role in the evolutionary transitions between land and aquatic environments in both Pseudosuchia and Testudinata. To do so, we measured the bone porosity as a proxy for vascular density in a set of dermal plates before performing phylogenetic comparative analyses. For both lineages, the dermal plate porosity obviously varies depending on the animal lifestyle, but these variations prove to be highly driven by phylogenetic relationships. We argue that the complexity of multi-functional roles of the post-cranial dermal skeleton in both Pseudosuchia and Testudinata probably is the reason for a lack of obvious physiological signal, and we discuss the role of the dermal shield vascularization in the evolution of these groups. This article is part of the theme issue ‘Vertebrate palaeophysiology’.

show abstract

The largest thalattosuchian (Crocodylomorpha) supports teleosaurid survival across the Jurassic-Cretaceous boundary

Cited by 48 publications

References 58 publications

Razanandrongobe sakalavae,a gigantic mesoeucrocodylian from the Middle Jurassic of Madagascar, is the oldest known notosuchian

Razanandrongobe sakalavae,a gigantic mesoeucrocodylian from the Middle Jurassic of Madagascar, is the oldest known notosuchian

Increased pliosaurid dental disparity across the Jurassic–Cretaceous transition

The evolution of dermal shield vascularization in Testudinata and Pseudosuchia: phylogenetic constraints versus ecophysiological adaptations

Contact Info

Product

Resources

About