Sacisaurus agudoensis Ferigolo and Langer, 2007

Nesbitt, Sterling J., 2011, The Early Evolution Of Archosaurs: Relationships And The Origin Of Major Clades, Bulletin of the American Museum of Natural History 2011 (352), pp. 1-292 : 48-49

Sacisaurus agudoensis Ferigolo and Langer, 2007

AGE: Late Carnian–early Norian ( Ferigolo and Langer, 2007).

OCCURRENCE: Santa Maria 2 sequence. Top of the Alemoa Member of the Santa Maria Formation or base of the Caturrita Formation.

HOLOTYPE: MCN PV10041, partial left mandibular ramus.

REFERRED MATERIAL: Dentaries (MCN PV10042, PV10043, PV10044, PV10061, PV10048); MCN PV10050, maxilla; MCN PV10051, postorbital; vertebrae (MCN PV10028, PV10029, PV10032, PV10090, PV10097); MCN PV10033, scapula; MCN PV10100, ilium; pubes (MCN PV10023, PV10024); MCN PV10025, ischium; femora (MCN PV10009, PV10010, PV10011, PV- 10013, PV10014, PV10015, PV10016, PV- 10018, PV10019, PV10063, PV10075); MCN PV10020, tibia.

REMARKS: Sacisaurus was described by Ferigolo and Langer (2007) from a multitaxic bonebed from the Santa Maria sequence. The holotype was picked from a collection of tens of individuals (counted from femora) as a distinct dentary, and all crania and postcrania were subsequently referred to the taxon ( Ferigolo and Langer, 2007). I agree with the authors for most of their assignments because of the similarity of most of the material to Silesaurus . However, remains of a basal saurischian dinosaur were found in the same bed among the disarticulated skeletons of Sacisaurus (S.J.N., personal obs). An ectopterygoid (MCN PV10049) assigned to Sacisaurus appears too large for that taxon and possibly belongs to a saurischian. As described by Ferigolo and Langer (2007), Sacisaurus is very similar to Silesaurus , a non-dinosaurian dinosauriform.

Ferigolo and Langer (2007) provided the following diagnosis: dinosauriform differing from other known basal members of the group, except Silesaurus opolensis and ornithischians, for the presence of an edentulous mandibular rostral portion. This jaw segment differs from that of S. opolensis because its front tip is not dorsally curved, and from that of ornithischians because it does not form a typically single (unpaired) predentary, but articulates to its counterpart in the midline.

KEY REFERENCES: Ferigolo and Langer, 2007.