PEIROSAURINAE, Geroto & Bertini, 2019

Geroto, Caio Fabricio Cezar & Bertini, Reinaldo J., 2019, New material of Pepesuchus (Crocodyliformes; Mesoeucrocodylia) from the Bauru Group: implications about its phylogeny and the age of the Adamantina Formation, Zoological Journal of the Linnean Society 185, pp. 312-334 : 329

PEIROSAURINAE SUBFAM. NOV.

urn:lsid:zoobank.org:act:647D2A18-0461-45A6-8304-72FFF18F427C

Diagnosis

Crocodyliformes with a heavily sculpted mandible and skull ( Gasparini, 1982; Gasparini et al., 1991); moderately high snout and a large wedged maxillary process inserted dorsolaterally between the premaxilla; a high maxillary notch; anterolaterally oriented external nares separated by the nasals; nasals lacking contact with the lacrimals; large and paired supraorbitals; broad and partly divided internal nares located between the palatine and pterygoid; a broad and anteroventrally inclined basisphenoid that is exposed only in occipital view; a supraoccipital that does not take up part of the cranial roof; the basioccipital has an elongated central crest and heavy lateral bumps; two to three teeth posterior to the anterior margin of the suborbital fenestra; subcircular teeth that are moderately compressed, with anterior and posterior serrated edges. Additionally, P. torminni , U. terrificus and M. arrudacamposi also have this nasal process.

Etymology

Peirosaurinae was established as the name of the subfamily based on the family Peirosauridae ( Gasparini, 1982) .

Phylogenetic definition

Peirosaurus torminni Price, 1955 and all Crocodyliformes that share a more recent common ancestor with P. torminni than with N. terrestris Woodward, 1896 , B. pachecoi Price, 1945 , S. huenei Price, 1950 , I. jesuinoi Price, 1955 , P. deiseae Campos et al., 2011 , B. franciscoi Iori & Carvalho, 2012 , A. gomesii Price, 1959 , S. icaeorhinus Simpson, 1937 , M. amarali Carvalho & Bertini, 1999 , and C. niloticus Laurent, 1768 .

Discussion

Peirosaurinae ( Fig. 9 ; node 156 ; refer to the Supplementary Information Data S3 for the consensus tree with the numbered node) consists of H. rebouli , L. palpebrosus , G. peirosauroides , Barcinosuchus gradilis , P. torminni , U. terrificus and M. arrudacamposi . A clade supported by 13 unambiguous synapomorphies was recovered based on: skull height in posterior view higher than wide (10.0); anteroposterior length of the premaxilla in relationship to the rostrum long (> 30% of the total length of the rostrum) (11.1); a premaxilla with a wedge-like process of the maxilla on the lateral surface of the premaxillary–maxillary suture (13.1); perinarial fossa facing anterolaterally (20.2); a foramen on the posterior surface of the base of the postorbital bar (67.3); posterodorsal inclination of the external surface of the occipital portion of the squamosal (110.1); shape of the dentary near the mandibular symphysis, forming an acute angle (183.0); dorsal edge of the dentary in the lateral view with two concave festooned regions (195.2); ziphodont teeth (219.0); lateral or anterolateral external nares (248); a foramen in the perinarial depression of the premaxilla (249.1); a notch for hypertrophied mandibular caniniform teeth on the premaxilla–maxilla suture, with a medial bent border of the premaxilla and maxilla (252.1); and reduced participation of the maxilla at the anterior margin of the suborbital fenestra (264.1).

The aim of this analysis was to provide some internal stability to Peirosauridae , thus both Hamadasuchus and Uberabasuchus were not chosen as internal specifiers of the subfamily Peirosaurinae , given the problems related to specimens of these taxa. The holotype of Hamadasuchus has some differences compared with a more complete specimen described by Larsson & Sues (2007) and the MNHN specimen (MRS 3101). A polytomy between P. torminni , M. arrudacamposi and U. terrificus is caused by an overlap of characteristics with Uberabasuchus recovered in a different position within node 153. Martinelli et al. (2012) and Lio et al. (2015) proposed that P. torminni and U. terrificus are synonymous based on morphological similarities, such as the premaxillary length relative to the rest of the rostrum. The clade is sustained by six non-ambiguous synapomorphies (node 153, Supplementary Information Data S3), hinting that the genus might be the same as the three taxa. That revision, however, is not the scope of this contribution.

Figures

Figure 1. Map of the Bauru Group (modified from Fernandes & Coimbra, 1996).

Figure 2. MCT 1723-R, anterior portion of the rostrum. A, D, dorsal view. B, E, ventral view. C, F, left lateral view. Grey areas are associated sediments; hatched areas are broken parts. Scale bars represent 5 cm.

Figure 3. MCT 1723-R, rostrum.A, B, dorsal views. C, D, ventral views. Grey areas are associated sediments; hatched areas are broken parts. Scale bars represent 5 cm.

Figure 4. MCT 1723-R, rostrum in lateral views. A, B, left lateral views. C, D, right lateral views. Grey areas are associated sediments; hatched areas are broken parts. Scale bars represent 5 cm.

Figure 5. Palatal surfaces of the maxillary from A, Pepesuchus deiseae (MCT 1788-R), with an anterior portion of the palatines showing a tipping point, compared with B, MCT 1723-R, with a broad and round anterior portion. Grey areas are associated sediments; hatched areas are broken parts. Scale bars represent 5 cm.

Figure 6. MCT 1723-R, mandible. A, B, distal views. C, D, ventral views. Grey areas are associated sediments; hatched areas are broken parts. Scale bars represent 5 cm.

Figure 9. Calibrated cladogram for the consensus strictus for the three most parsimonious trees, depicting only Mesoeucrocodylia. For the complete cladogram, refer to Supplementary Information Data S3. Mesoeucrocodylia. For the complete cladogram, refer.