formation

The distictive banding of the Morrison Formation, a group of rock layers that occur throughout Dinosaur National Monument. The formation originated as muds and sands laid down by ancient rivers, and some of its outcrops have been found to contain 150-million-year-old dinosaur fossils like those found at the monument's Dinosaur Quarry.

Bituminous claystone, Lower Jurassic, Hesselberg, Middle Franconia. Sedimentary rock of very thin laminated layers (particles less than 0,0002 mm). Rock formation is known for its rich fossil findings, ex. Ichthyosaur.

Hell Creek Formation near Ft. Peck Reservoir, Montana

J. D. Porfiri excavating the holotype of Diuqin lechiguanae from the Bajo de la Carpa Formation.

Outcrops of the Foremost Formation along the Milk River.

Wayan Formation eggshell. Eggshell of the oogenus Macroelongatoolithus on a Wayan Formation outcrop. Image used courtesy of the USFS Paleontology Program

Restoration of the spinosaurid dinosaur Siamosaurus in the Sao Khua Formation palaeoenvironment, with Sunosuchus in the middle left and a herd of Phuwiangosaurus in the background. References: Siamosaurus based on tooth specimens [1] and the neural spine of a possibly referable skeleton[2], with other missing elements filled in with relatives (Suchomimus[3], Baryonyx[4], IchthyovenatorFile:Ichthyovenator_laosensis_skeletal_reconstruction_by_PaleoGeek.png). Phuwiangosaurus based on skeletal by Suteethorn et al. (2009)[5] and missing elements of skull of EuhelopusFile:Euhelopus.png. Sunosuchus based on Suteethorn and Ingavat (1983)[6] and missing elements based on Goniopholis[7].

Stratigraphy, Tremp Formation in Spain.

Stratigraphy, Tremp Formation in Spain.

Sibişel River (Strei) near the Sânpetru Mesozoic Formation, Romania

Geographical and geological location of the Los Quiñones site in the Blesa Formation. (A) Geological map of the Iberian Peninsula; (B) Location of the paleogeographical sub-basins within the Maestrazgo Basin; and (C) location of the Los Quiñones site close to the village of Obón (modified from14).

Halisaurus sp. from the Quiriquina Formation. Originally thought to represent Plotosaurus.

Highly derived mosasaur from the Moreno Formation that could grow to large sized. Converges with basal ichthyosaurs in bauplan- and has tuna-like swimming motion.

Skeletal reconstructions of Dinosaur Park Formation caenagnathids. Skeletal reconstructions of Citipes elegans (left), Chirostenotes pergracilis (middle), and Caenagnathus collinsi (right), showing variation in skeletal representation and body size. Previously referred material is indicated in white and newly referred material is indicated in red for each taxon. Blue asterisks indicate elements that have been histologically sampled for each taxon. Citipes elegans: dentaries, metatarsal IV; Chirostenotes pergracilis: dentaries, tibia; Caenagnathus collinsi: pubis.

Tarsometatarsi of caenagnathids from the Upper Campanian Dinosaur Park Formation, Dinosaur Provincial Park, Alberta, Canada. A. TMP 1993.036.0181 (Chirostenotes pergracilis). B. TMP 1982.016.0006 (Citipes elegans). C. ROM 781 (Citipes elegans holotype). D. TMP 1996.012.0141 (Citipes elegans). Tarsometatarsi in proximal (A1–D1), anterior (A2–D2), and posterior (A3–D3) views.

Original figure caption: Trackway S1 (Eosauropus sp.), here attributed to a sauropod trackmaker based on pedal synapomorphies; trackmaker is moving towards the south-west. Two consequtive pes impressions of a tridactyl Grallator [i.e. a theropod] trackway can be seen left to the S1 trackway. Note: The tracks are preserved on a bedding plane of a thin siltstone bed of the Late Triassic Fleming Fjord Formation of East Greenland. A) shows a photograph of the trackway(s) as preserved on the bedding plane (i.e. as concave epireliefs); B) shows a color shaded relief map based on a high-resolution photogrammetric 3D-model of the bedding plane; C) is an interpretative outline drawing of the S1 trackway; abbreviations: LM = left manus (i.e. forefoot), LP = left pes (i.e. hindfoot), RM = right manus, RP = right pes, numbers increase in walking direction.