Dalton Wells Quarry, BYU Loc. 7510 (Cretaceous of the United States)

Also known as State of Utah Loc. 42Gr001V, Dalton Well

Where: Grand County, Utah (38.7° N, 109.7° W: paleocoordinates 38.6° N, 60.2° W)

• coordinate estimated from map

• outcrop-level geographic resolution

When: Yellow Cat Member (Cedar Mountain Formation), Early/Lower Aptian (125.5 - 122.5 Ma)

• stacked succession of 4 bonebeds below footprint level, and approx. 2 m above base of member in this area

•Detrital zircons from the quarry and adjacent, lateral equivalents provide a maximum depositional age of 125 Ma, indicating the horizon is no older than early Albian (Eberth et al., 2006)

• group of beds-level stratigraphic resolution

Environment/lithology: crevasse splay; pebbly, intraclastic, silty, conglomeratic mudstone

• "Bonebed sediments were deposited by subaerial debris flows (cohesive mudflows)...may have been triggered by intense rainfall or seismic events...Bonebeds were most likely deposited in a backbulge setting characterized by alluvial-lacustrine paleoeonvironments and a warm-to-hot, seasonally wet-and-dry climate."
• "a 4 m thick, conglomeratic, silty, mudstone lithosome...[it] is nearly devoid of internal sedimentary structures. The largest clasts are bones (up to 1.5 m long) and 10 cm in diameter, well rounded, chert pebbles. With the exception of the larger bones, the clasts are matrix supported. Mud drapes in the middle of the conglomeratic mudstone..."

Size classes: macrofossils, mesofossils

Collected by J. Kay, J. Jenson, L. Ottinger, B. Britt, J. Kirkland in 1968, 1994-1997

Collection methods: bulk, mechanical,

• entered as including 1400 specimens, but Britt et al. 2006 state that there are "4210 collected specimens"

Primary reference: P. M. Galton and J. A. Jensen. 1975. Hypsilophodon and Iguanodon from the Lower Cretaceous of North America. Nature 257:668-669 [M. Carrano/M. Carrano]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 27025: authorized by Matthew Carrano, entered by Matthew Carrano on 13.11.2002, edited by Matthew Oreska and Philip Mannion

Creative Commons license: CC BY (attribution)

Taxonomic list

 Dicondylia -
Coleoptera indet.10 Linnaeus 1758 beetle
Silphidae or Histeridae, but Dermestidae unlikely
 Testudines -
"Chelonia indet." = Testudines6
"Chelonia indet." = Testudines6 Batsch 1788 turtle
 Ornithodira -
Ornithodira indet.6 Gauthier 1986 ornithodiran
Pterosauria or Aves
 Saurischia -
Sauropoda indet.1 sauropod
humerus (BYU 14052)
Moabosaurus utahensis n. gen. n. sp.4 Britt et al. 2017 sauropod
Moabosaurus utahensis4 Britt et al. 2017 sauropod
Macronaria indet.1 Sereno 1997 sauropod
caudal vertebra centrum (BYU 14817); dorsal vertbra (BYU 14855); caudal vertebra (BYU 11042)
 Saurischia - Brachiosauridae
Brachiosauridae indet.4 Riggs 1904 brachiosaurid
Brachiosauridae indet.4 Riggs 1904 brachiosaurid
left ischium (BYU 14072)
 Avetheropoda - Dromaeosauridae
Utahraptor ostrommaysi5 Kirkland et al. 1993 coelurosaur
tibia (BYU 18082), caudal vertebra (BYU 19000)
 Avetheropoda -
Ornithomimosauria indet.2 Barsbold 1976 ornithomimosaur
Nedcolbertia justinhoffmanni9 Kirkland et al. 1998 coelurosaur
 Ornithischia - Polacanthidae
Gastonia burgei8 Kirkland 1998 ornithischian
 Neornithischia - Iguanodontidae
Iguanodontidae indet.5 Bonaparte 1850 iguanodontid
"a tall-spined Ouranosaurus-like iguanodontid"
 Neornithischia -
Iguanodon ottingeri n. sp.7 Galton and Jensen 1979 bird foot dinosaur
caudal vertebra (BYU 9420)
 Crocodylia - Crocodylidae
Crocodylidae indet.6 Cuvier 1807 crocodile
 Choristodera -
Neochoristodera indet.3 Evans and Hecht 1993 choristodere