Sarcosuchus hartti, HARTTI (MARSH, 1869)

Souza, Rafael G., Figueiredo, Rodrigo G., Azevedo, Sérgio A. K., Riff, Douglas & Kellner, Alexander W. A., 2020, Systematic revision of Sarcosuchus hartti (Crocodyliformes) from the Recôncavo Basin (Early Cretaceous) of Bahia, north-eastern Brazil, Zoological Journal of the Linnean Society 188, pp. 552-578 : 556

SARCOSUCHUS HARTTI ( MARSH, 1869)

( FIGS 3–7 , 10A )

Basionym: Crocodylus hartti Marsh, 1869 .

Synonym: Goniopholis hartti ( Marsh, 1869) Mawson & Woodward, 1907 .

Lectotype (designated here): YPM 516.

Comments: The syntypes are the teeth listed by Marsh (1869), but he did not present the collection numbers of those teeth and only referred to those described and illustrated by Allport (1860: pl. XVI, figs 1–3, 5). The tooth YPM 516 mistakenly designated as holotype by Norell & Storrs (1989) must be treated as the lectotype and all other teeth studied by Marsh are paralectotypes.

Referred material: A large-sized and incomplete mandible with some preserved teeth (BMNH R3423), a fragment of a right mandibular ramus with a few crosssectioned teeth bases inside the alveoli (MN 7459-V), three isolated teeth crowns with anastomosing enamel (BMNH R 3079, MN 7460-V, MN 7461-V).

Horizon and locality: The type specimens and referred material were recovered from strata of the Lower Cretaceous Recôncavo Basin, Bahia Supergroup, Ilhas Group (Late Hauterivian–Early Barremian). No further details are available.

Revised diagnosis: Sarcosuchus hartti is diagnosed by the following combination of characters (autapomorphies indicated by *): false ziphodont teeth; heterodont dentition with large and tall anterior caniniforms and circular and blunt posterior teeth; smooth crenulations on both carinae; delicate longitudinal and oblique lines forming an anastomosed enamel surface*; elliptic dentary alveoli; ventral depressed and sculptured area between the mandibular symphysis and the medial alveolar margin*; double festooned mandible with the first concavity being the deeper one and located between the fourth and tenth alveoli, while the second one is shallow and is placed between the 13 th and the 21 st alveoli*. Based on the phylogenetic inference, two characters are considered autapomorphies in all trees: the dorsal margin of dentary in lateral view is double festooned (Char. 224: 0 -> 4) and the posterior dentitions of maxilla and dentary are elliptical (Char. 265: 1 -> 0).

Figures

Figure 3. Sarcosuchus hartti, teeth. A, YPM 516, Lectotype, in mesial view. B, BMNH R2983, in mesial (?) view. C, BMNH R2983, in distal (?) view. D, BMNH R3079, in mesial (?) view. E, BMNH R3079, in distal (?) view. F, MN 7460-V, in distal (?) view. G, MN 7460-V, in apical view. H, MN 7461-V, in distal (?) view. I, MN 7461-V, in apical view. Scale bar: 1 cm.

Figure 4. Sarcosuchus hartti, teeth in detail. The enamel structures are shown in the red boxes. A, YPM 516, Lectotype, in mesial view. B, MN 7460-V, in distal (?) view. C, BMNH R3079, in distal (?) view. D, MN 7461-V, in distal (?) view. Scale bar: 1 cm.

Figure 5. Sarcosuchus hartti, mandible (BMNH R 3423). A, left lateral view. B, ventral view. C, anterior view. D, dorsal view. Scale bar: 10 cm.

Figure 6. Sarcosuchus hartti, schematic drawing of the mandible (BMNH R 3423). A, left lateral view. B, ventral view. C, anterior view. D, dorsal view. Abbreviations: 1st, first dentary alveolus; 4th, fourth dentary alveolus; pte, preserved teeth; 11th, eleventh dentary alveolus; 16th, sixteenth dentary alveolus; 22nd, twenty-second dentary alveolus; d-spl, suture between dentary and splenial. Scale bar: 10 cm.

Figure 7. Sarcosuchus hartti, right hemimandible (MN 7459-V). A, dorsal view. B, ventral view. C, medial view. D, left lateral view. Abbreviations: 7th, seventh dentary alveoli; 16th, sixteenth dentary alveoli; 20th, twentieth dentary alveoli; d-spl, suture between dentary and splenial; d-d, suture between dentary bones; Mc, Meckel’s Canal; dp, dentary pits of the ventral ornamentation; op, occlusion pits; gr, groove region. Scale bar: 3 cm.

Figure 10. Schematic drawings of the anterior end of the mandible in selected pholidosaurids. All drawings in dorsal view. A, Sarcosuchus hartti (BMNH R3423). B, Sarcosuchus imperator from Buffetaut & Taquet (1977). C, PRC102-143 referred to C. thailandicus from Martin et al. (2013). D, Sunosuchus phuwiangensis from Buffetaut & Ingavat (1983). E, Pholidosaurus purbeckensis from Martin et al. (2016). F, Elosuchus cherifiensis from de Broin (2002). G, Fortignathus felixi from Young et al. (2017). H, CAS42-20 holotype of Chalawan thailandicus from Buffetaut & Ingavat (1984). I, Turanosuchus aralensis from Halliday et al. (2015). Not to scale.