Neothalattosuchia, Young, Wilberg, Johnson, Herrera, Brandalise, Andrade, Brignon, Sachs, Abel, Foffa, Fernández, Vignaud, Cowgill & Brusatte, 2024

Young, Mark T., Wilberg, Eric W., Johnson, Michela M., Herrera, Yanina, Brandalise, Marco de Andrade, Brignon, Arnaud, Sachs, Sven, Abel, Pascal, Foffa, Davide, Fernández, Marta S., Vignaud, Patrick, Cowgill, Thomas & Brusatte, Stephen L., 2024, The history, systematics, and nomenclature of Thalattosuchia (Archosauria: Crocodylomorpha), Zoological Journal of the Linnean Society 200 (2), pp. 547-617 : 587-590

Neothalattosuchia , new clade name (PhyloCode)

RegNum registration number 1014.

Etymology

‘New sea crocodiles’. Neo - from the Ancient Greek (νέος, néos) for young or new. Thalatto - is from the classical Ancient Greek (θᾰ́λᾰ́ττᾰ́, thálatta) for sea. Suchus is the Neo-Latinized form of the Greek Soukhos (σοῦΧος), which appears to have been the name of an individual tamed crocodile that lived in Arsinoite nome, in Ancient Egypt ( Larcher 1844: 286). The suffix - suchus is today used to refer to crocodiles, crocodylian relatives, or crocodylian analogues. The Neo-Latin suffix - ia denotes an abstract noun of feminine grammatical gender.

Geological range

Early Jurassic (Hettangian–Sinemurian) to Early Cretaceous (earliest Aptian) ( von Huene and Maubeuge 1952, 1954, Gasparini 1985, Godefroit 1994, Gasparini et al. 2000, Chiarenza et al. 2015, Sachs et al. 2020, Hicham et al. 2023).

PhyloCode phylogenetic definition

The smallest clade within Thalattosuchia containing Macrospondylus bollensis ( Jäger 1828) , Platysuchus multiscrobiculatus ( Berckhemer 1929) , Pelagosaurus typus Bronn 1842 and Thalattosuchus superciliosus (Blainville in Eudes-Deslongchamps 1852).

Reference phylogeny

Fig. 3 .

PhyloCode diagnostic apomorphies

Crocodylomorphs with the following unique combination of characters (6): antorbital cavity much smaller than the orbit in terms of area (173.0) and length (174.0); trigeminal fossa is well developed posteriorly to the fenestra (i.e. fossa very broadly exposed on the quadrate) (438.1); presence of two distinct foramina within the trigeminal fossa (440.1); basioccipital tuberosities are large (459.1); the tibiae are evidently shorter than the femora (with some Toarcian teleosauroid species falling in states 1 and 2) (809.2).

Composition

Teleosauroidea (which is composed of Machimosauridae and Teleosauridae ) and Metriorhynchoidea (successively comprising of Pelagosaurus , Teleidosaurus , Magyarosuchus , Opisuchus , Eoneustes , Zoneait , and Metriorhynchidae ).

Comments

Authorship: This is a new nomen.

Prior phylogenetic definition: This clade has never been phylogenetically defined.

Content: This clade is what is normally ‘pictured’ as Thalattosuchia —containing the two large radiations Teleosauroidea and Metriorhynchoidea . The chosen specifiers ensure that the major thalattosuchian radiations are represented (e.g. Teleosauridae , Machimosauridae , and Metriorhynchidae ), as well as ‘transitional forms’ such as Pelagosaurus typus. Under this definition, only Turnersuchus hingleyae and Plagiophthalmosuchus gracilirostris ( Fig. 20 ) fall outside of Neothalattosuchia . Prior to our analyses, only Turnersuchus hingleyae from the Pliensbachian had been recovered as an early diverging thalattosuchian ( Wilberg et al. 2023).

Note: As Neothalattosuchia is above the family-group, only Articles 1–4, 7–10, 11.1–11.3, 14, 27, 28, and 32.5.2.5 of the Zoological Code apply (as per Article 1.2.2).

Figures

Figure 3. The equal weights, no constraints strict consensus topology (C0). Length = 4164, CI = 0.303, RI = 0.831, RC = 0.251, HI = 0.697, number of most parsimonious cladograms hit the hold limit.Phylogeny pruned to highlight Thalattosuchia (see Supporting Information, Appendix S2, Fig. S1 for the entire topology). A, Crocodylomorpha; B, Crocodyliformes; C, Thalattosuchia; D, Neothalattosuchia; E, Teleosauridae; F, Teleosaurinae; G, Aeolodontini; H, Machimosauridae; I, Machimosaurinae; J, Machimosaurini; K, Euthalattosuchia; L, Metriorhynchidae; M, Metriorhynchinae; N, Rhacheosaurini; O, Geosaurinae; P, Geosaurini. Green lines highlight non-neothalattosuchian thalattosuchians, orange lines highlight teleosauroid thalattosuchians, and blue lines highlight metriorhynchoid thalattosuchians.Images from PhyloPics.org, with the teleosauroid by Scott Hartman, and the metriorhynchid by Dmitry Bogdanov (vectorized by T. Michael Keesey), the only change made was to their colouration, and their license is: https://creativecommons.org/licenses/by/3.0/.

Figure 20. The type specimens of the non-neothalattosuchian thalattosuchian Plagiophthalmosuchus gracilirostris. A, holotype NHMUK PV OR 14792, nearly complete skeleton in dorsal view; B, paratype NHMUK PV OR 15500, skull in lateral view. Scale bar for A equals 30 cm, and the scale bar for B equals 10 cm.