Conor's Microsite (CM) (Cretaceous of the United States)

Where: Garfield County, Montana (47.6° N, 106.9° W: paleocoordinates 54.5° N, 79.4° W)

• coordinate estimated from map

• small collection-level geographic resolution

When: Hell Creek Formation, Maastrichtian (72.1 - 66.0 Ma)

• lower part of formation

• bed-level stratigraphic resolution

Environment/lithology: crevasse splay; paleosol/pedogenic, fine-grained, gypsiferous, intraclastic siltstone

• "deposition under lower current velocities or by suspension settling...fluid movement during the onset of fossil deposition, with waning velocities toward the top of the deposit..paleosol development with possible wet-dry cycles...a crevasse-splay deposit."
• "comprises a sequence of interbedded mudstone, siltstone, and well as gypsum, amber nodules, rounded clay clasts, and slickensides. The fossiliferous unit was deposited atop mottled clay with abundant in site traces of stems and roots...The quarried horizon is capped by...a coarsening-upward, mud-rich siltstone containing traces of plant stems. The fossiliferous unit falls within a laminated fine-grained facies...Rip-up clasts and millimeter-scale lenses of coarser sediments."

Size class: mesofossils

Preservation: mold/impression

Reposited in the UCM

Collection methods: bulk, quarrying, sieve,

Primary reference: L. E. Wilson. 2008. Comparative taphonomy and paleoecological reconstruction of two microvertebrate accumulations from the Late Cretaceous Hell Creek Formation (Maastrichtian), eastern Montana. Palaios 23:289-297 [M. Carrano/M. Carrano]more details

Purpose of describing collection: taphonomic analysis

PaleoDB collection 85498: authorized by Matthew Carrano, entered by Matthew Carrano on 02.01.2009

Creative Commons license: CC BY (attribution)

Taxonomic list

Bivalvia indet. Linnaeus 1758 clam
Gastropoda indet. Cuvier 1797 snail
 Acipenseriformes - Acipenseridae
Acipenser sp. Linnaeus 1758 sturgeon
 Holostei -
Holostei "indet. A" Müller 1846
Holostei "indet. B" Müller 1846
 Lepisosteiformes - Lepisosteidae
Lepisosteus sp. Agassiz 1843 gar
 Proteida - Batrachosauroididae
Prodesmodon copei Estes 1964 salamander
Opisthotriton kayi Auffenberg 1961 salamander
 Caudata - Urodela
Habrosaurus dilatus Gilmore 1928 siren
Scapherpeton tectum Cope 1876 salamander
 Testudines - Trionychidae
Trionychidae indet. Gray 1825 softshell turtle
 Testudines - Baenidae
Baenidae indet. Cope 1882 turtle
 Testudines - Nanhsiungchelyidae
Basilemys sp. Hay 1902 turtle
 Testudines - Adocidae
Adocus sp. Cope 1868 turtle
 Testudines - Panchelydridae
 Avetheropoda - Dromaeosauridae
Richardoestesia isosceles Sankey 2001 coelurosaur
Richardoestesia gilmorei Currie et al. 1990 coelurosaur
Saurornitholestes langstoni Sues 1978 coelurosaur
 Avetheropoda -
Paronychodon lacustris Cope 1876 coelurosaur
 Avetheropoda - Tyrannosauridae
Tyrannosauridae indet. Osborn 1906 tyrannosaurid
 Ornithischia - Ankylosauridae
Ankylosauridae indet. Brown 1908 ornithischian
 Neornithischia - Pachycephalosauridae
Pachycephalosauridae indet. Sternberg 1945 ornithischian
 Neornithischia - Ceratopsidae
Ceratopsidae indet. Marsh 1888 ceratopsid
 Neornithischia - Hadrosauridae
Hadrosauridae indet. Cope 1869 hadrosaurid
 Eosuchia -
Plantae indet. Haeckel 1866
leaf impressions, seeds