Triassic

Lower Triassic fossil footprint (ichnite) of the ichnogenus Chirotherium, probably caused by an early archosaur, and first discovered 1833 in Hildburghausen (Thuringia, Germany). This specimen, however, ist from the Helsby Sandstone of the Storeton Quarry near Liverpool. Its species name is Chirotherium storetonense.[1]

Right hind limb of the sauropodomorph dinosaur Musankwa sanyatiensis gen. et sp. nov. (NHMZ 2521) from the Pebbly Arkose Formation (Norian, Upper Triassic) of Spurwing Island, Zimbabwe. A. Right femur in posterior (A1), lateral (A2), anterior (A3), medial (A4), proximal (A5), and distal (A6) views. B. Right tibia with conjoined astragalus in anterior (B1), lateral (B2), posterior (B3), medial (B4), and proximal (B5) views.

Left maxilla of the silesaurid Agnosphitys cromhallensis from the Late Triassic (Rhaetian) of England.

Pantydraco caducus, a sauropodomorph from the Late Triassic or Early Jurassic of England, after Yates, 2003, pencil drawing, digital coloring

Schädel, vorderer Abschnitt der Wirbelsäule und Elemente des Schultergürtels von Paraplacodus broili (Exemplar-Nr. BSP 1953 XV 5) aus der Grenzbitumenzone (Mittel-Trias) des Monte San Giorgio (Tessin) in linksseitiger Ansicht, ausgestellt im Paläontologischen Museum München. Die Länge des Schädels beträgt ca. 12 cm.[1]

Rendition of possible appearance of the dinosaur genus Nyasasaurus from the Middle Triassic, possibly the earliest known dinosaur. Black portions represent the partial skeletal fragments (a humerus and six vertebrae) from one specimen blue portions represent fragments from a second specimen (three cervical vertebrae) on which the current likely form of the animal is based.

Various fossils pertaining to the holotype of the Triassic ichthyosaur Toretocnemus californicus. This image is derived from plate 24 in Merriam (1903), done by an uncredited artist. The arrangement of the individual figures has been modified from the original. Original description: Toretocnemus californicus n. gen. and sp. Figures reproduced natural size from the type specimen. Fig. 1. — Inferior side of right posterior limb. t, tibia. Fig. 2. — Right anterior limb. r, radius. Fig. 3.— Pelvic arch. Fig. 4. — Middle dorsal vertebrae and a rib from the same region.

Early Triassic marine vertebrate apex predators during the Griesbachian to Smithian interval (left) and the Spathian to Anisian interval (right). Predators not exactly to scale; see text and Tables S1–S2 for details on body size and stratigraphic occurrence. Marine vertebrate apex predators: 1, Wantzosaurus (trematosaurid ‘amphibian’); 2, Fadenia (eugeneodontiform chondrichthyan); 3, Saurichthys (actinopterygian ambush predator); 4, Rebellatrix (fork-tailed actinistian); 5, Hovasaurus (‘younginiform’ diapsid reptile); 6, Birgeria (fast-swimming predatory actinopterygian); 7, Aphaneramma (trematosaurid ‘amphibian’); 8, Bobasatrania (durophagous actinopterygian); 9, hybodontoid chondrichthyan with durophagous (e.g. Acrodus, Palaeobates) or tearing-type dentition (e.g. Hybodus); 10, e.g., Mylacanthus (durophagous actinistian); 11, Tanystropheus (protorosaurian reptile); 12, Corosaurus (sauropterygian reptile); 13, e.g., Ticinepomis (actinistian); 14, Mixosaurus (small ichthyosaur); 15, large cymbospondylid/shastasaurid ichthyosaur; 16, neoselachian chondrichthyan; 17, Omphalosaurus skeleton (possible durophagous ichthyosaur); 18, Placodus (durophagous sauropterygian reptile).

Early Triassic marine vertebrate apex predators during the Griesbachian to Smithian interval (left) and the Spathian to Anisian interval (right). Predators not exactly to scale; see text and Tables S1–S2 for details on body size and stratigraphic occurrence. Marine vertebrate apex predators: 1, Wantzosaurus (trematosaurid ‘amphibian’); 2, Fadenia (eugeneodontiform chondrichthyan); 3, Saurichthys (actinopterygian ambush predator); 4, Rebellatrix (fork-tailed actinistian); 5, Hovasaurus (‘younginiform’ diapsid reptile); 6, Birgeria (fast-swimming predatory actinopterygian); 7, Aphaneramma (trematosaurid ‘amphibian’); 8, Bobasatrania (durophagous actinopterygian); 9, hybodontoid chondrichthyan with durophagous (e.g. Acrodus, Palaeobates) or tearing-type dentition (e.g. Hybodus); 10, e.g., Mylacanthus (durophagous actinistian); 11, Tanystropheus (protorosaurian reptile); 12, Corosaurus (sauropterygian reptile); 13, e.g., Ticinepomis (actinistian); 14, Mixosaurus (small ichthyosaur); 15, large cymbospondylid/shastasaurid ichthyosaur; 16, neoselachian chondrichthyan; 17, Omphalosaurus skeleton (possible durophagous ichthyosaur); 18, Placodus (durophagous sauropterygian reptile).

Photograph of Museo civico di scienze naturali di Bergamo (MCSNB) 2888, the holotype specimen of Eudimorphodon ranzii ZAMBELLI 1973, a basal pterosaur from the Norian (middle Upper Triassic) of the Italian Alps.[1] ↑ see fig. 8A in Silvio Renesto (2006): A reappraisal of the diversity and biogeographic significance of the Norian (Late Triassic) reptiles from the Calcare di Zorzino. In: Jerry D. Harris, Spencer G. Lucas, Justin A. Spielmann, Martin G. Lockley, Andrew R.C. Milner, James I. Kirkland (eds.): The Triassic-Jurassic Terrestrial Transition. New Mexico Museum of Natural History and Science Bulletin 37:445–456 (online)

Figure description from the paper: "The segmented model of right lateral side of the skull of mixosaurid ichthyosaur Phalarodon fraasi (Merriam, 1910) PMO 235.393, from the Botneheia Formation, Middle Triassic of the Isfjorden area in Spitsbergen, Svalbard." References: Roberts, A.J.; Engelschiøn, V.S.; Hurum, J.H. (2022). "First three-dimensional skull of the Middle Triassic mixosaurid ichthyosaur Phalarodon fraasi from Svalbard, Norway". Acta Palaeontologica Polonica 67 (1): 51–62. DOI:https://doi.org/10.4202/app.00915.2021.

Figure description from the paper: "The segmented model of right lateral side of the skull of mixosaurid ichthyosaur Phalarodon fraasi (Merriam, 1910) PMO 235.393, from the Botneheia Formation, Middle Triassic of the Isfjorden area in Spitsbergen, Svalbard." References: Roberts, A.J.; Engelschiøn, V.S.; Hurum, J.H. (2022). "First three-dimensional skull of the Middle Triassic mixosaurid ichthyosaur Phalarodon fraasi from Svalbard, Norway". Acta Palaeontologica Polonica 67 (1): 51–62. DOI:https://doi.org/10.4202/app.00915.2021.

PLATE II(IX). Fig. 1. Anchisaurus colurus MARSH. All extant specimens in approximately 1/5 nat. size. Connecticut red sandstone (Upper Triassic). Manchester, Conn., USA. MARSH's original specimen, preserved at the Yale Museum, New Haven, Conn. Scale bar: 11 cm. Skull: see Pl. I [VIII], forefoot: see Pl. III [X], scapula, hindleg, and pubis: see figures in the text.

PLATE II(IX). Fig. 1. Anchisaurus colurus MARSH. All extant specimens in approximately 1/5 nat. size. Connecticut red sandstone (Upper Triassic). Manchester, Conn., USA. MARSH's original specimen, preserved at the Yale Museum, New Haven, Conn. Scale bar: 11 cm. Skull: see Pl. I [VIII], forefoot: see Pl. III [X], scapula, hindleg, and pubis: see figures in the text.

PLATE II(IX). Fig. 1. Anchisaurus colurus MARSH. All extant specimens in approximately 1/5 nat. size. Connecticut red sandstone (Upper Triassic). Manchester, Conn., USA. MARSH's original specimen, preserved at the Yale Museum, New Haven, Conn. Scale bar: 11 cm. Skull: see Pl. I [VIII], forefoot: see Pl. III [X], scapula, hindleg, and pubis: see figures in the text.

Partial skull of Shastasaurus pacificus (UCMP 9017) from the Late Triassic of California, USA, in (A) lateral, (B) dorsal, and (C) anterolateral view. Based on this skull, Shastasaurus has repeatedly been reconstructed with a long, tooth-bearing rostrum. However, note the slenderness of the lower jaw (B, C) and the strong anterior taper of the snout (B), both of which are more consistent with the abbreviated and toothless snout of Shastasaurus liangae comb. nov. than with the traditional long-snouted reconstruction of this skull (as, e.g., in references [22] and [23]).