The Early Evolution Of Archosaurs: Relationships And The Origin Of Major Clades Author Nesbitt, Sterling J. text Bulletin of the American Museum of Natural History 2011 2011-04-29 2011 352 1 292 http://www.bioone.org/doi/abs/10.1206/352.1 journal article 10.1206/352.1 0003-0090 5405335 Saurischia Seeley, 1887 5 Eusaurischia Padian et al., 1999 ORIGINAL DEFINITION: Birds and all dinosaurs that are closer to birds than they are to Ornithischia ( Gauthier, 1986 ) . REVISED DEFINITION: Node: The most inclusive clade containing Passer domesticus Linnaeus, 1758 , and Saltasaurus loricatus Bonaparte and Powell, 1980 , but not Triceratops horridus ( Marsh, 1889 ) (sensu Sereno, 2005) . TEMPORAL RANGE: Late Triassic (?Carnian–early Norian, Herrerasaurus ischigualastensis Reig, 1963 ) to Recent ( Passer domesticus Linnaeus, 1758 ). SUPPORT: (1) Subnarial foramen between the premaxilla-maxilla where the border of the foramen is present on both the maxilla and the premaxilla (12-1)*. (2) Lacrimal folds over ( 5 overhangs) the posterior/ posterodorsal part of the antorbital fenestra (38-1)*. (3) Ventral ramus of the opisthotic covered by the lateralmost edge of exoccipital in posterior view (111-1). (4) Foramen in the ventral part of the splenial (165-1)*. (5) Epipophyses present in posterior cervical vertebrae (cervicals 6–9) (187-1). (6) Hyposphene-hypantrum accessory intervertebral articulations in the posterior cervical and/or dorsal vertebrae (195-1)*. (7) First primordial sacral rib C-shaped in lateral view (209- 1)*. (8) Manual length accounts for more than 0.3 but less than 0.4 of the total length of humerus plus radius (247-1). (9) Distal carpal V absent (249-1)*. (10) Manual digit I, first phalanx (1.1) is the longest nonungual phalanx of the manus (253-1)*. (11) Lateral distal condyle strongly distally expanded relative to medial condyle of metacarpal I (254-1). (12) Metacarpal IV shaft width significantly narrower than that of metacarpals I–III (261-1). (13) Distal end of pubis expanded relative to the shaft ( 5 pubis boot) (283-1). (14) Cross section of the distal portion of the ischium subtriangular (293-2). (15) Deep groove between the lateral condyle and crista tibiofibularis on the distal surface of the femur (322-1). (16) Posterior prong of distal tarsal 4 pointed (350-1)*. (17) Distal tarsal 4 with a distinct medial process present in the anteroposteri- or middle of the element (351-1)*. (18) Astragalus, proximal surface possesses a marked rimmed and elliptical fossa posteri- or to the anterior ascending process (359- 1)*. Other possible synapomorphies: AC- CTRAN: Nasal possesses a posterolateral process that envelops part of the anterior ramus of the lacrimal (36-1). Absent in Herrerasaurus according to Langer and Benton (2006) ; nasal forms part of the dorsal border of the antorbital fossa (37- 1). Absent in Herrerasaurus according to Langer and Benton (2006) ; lacrimal as high as the orbit, and contacts the jugal at the level of the ventral margin of the orbit (39- 1). Absent in Herrerasaurus ; femur longer or about the same length as the tibia/fibula (299-0); rounded ridge ( 5 dorsolateral trochanter of some) on the dorsolateral margin of the proximal portion of the femur (307-1); proximal portion of metatarsal IV possesses an elongated lateral expansion that overlaps the anterior surface of metatarsal V (392-1); metatarsal V present and has a ‘‘poorly’’ developed first phalanx (399-1).