PBDB Collection

Crystal Geyser Quarry (UMNH VP Loc. 157) (Cretaceous to of the United States)

Also known as CGDQ, CGQ

Where: Grand County, Utah (38.9° N, 110.1° W: paleocoordinates 36.9° N, 59.4° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: Yellow Cat Member (Cedar Mountain Formation), Berriasian to Berriasian (145.0 - 132.9 Ma)

• base of member, fossils from basal units 1-3; date from sandy unit just above bonebed

•

•Joeckel et al. 2019: Of the 10 samples collected from the Yellow Cat Member for U–Pb zircon geochronology, nine are from mudstones and one is from a fine- to medium- grained sandstone at the base of the Yellow Cat Member (Table 1). Table 1 summarizes the Concordia ages, weighted mean ages and youngest single-grain ages from these samples. The youngest single-grain ages (Dickinson & Gehrels 2009) from all but one of the mudstones span a 206Pb/238U age range from 133.7 + 2.7 to 139.5 + 3.1 Ma (at 2σ uncertainty), within the Valanginian Stage of the Lower Creta- ceous. The remaining mudstone sample, which has a distinct sand component, and the sandstone sample from the base of the Yellow Cat Member have youngest single zircon grains with ages of 142.5 + 2.7 and 141.9 + 3.9 Ma that both fall into the preceding Berriasian Stage.

• group of beds-level stratigraphic resolution

Environment/lithology: spring; concretionary, pebbly, argillaceous, sandy mudstone and lenticular limestone

• "preserved in or near a spring"

• "The CGDQ consists of a basal, bone-bearing limestone; bone-bearing, sandy mudstone unit; interbedded sandy mudstone and limestone; and a silicified limestone caprock. The basal limestone layer has a maximum thickness of 12 cm and laterally pinches out to a pisolitic horizon. The overlying bone-bearing mudstone consists of smaller clay clasts, pisolites, isolated pebbles, carbonate nodules and concretions. The nodules and concretions increase toward the top of the bone-bearing mudstone. Bones are often encrusted with micrite calcite, and some concretions contain dinosaur bone or bone fragments."

Size class: macrofossils

• Falcarius utahensis most common taxon

Preservation: concretion

Collected by Utah Geol. Survey & UMNH in 2001-

Collection methods: quarrying, surface (float), surface (in situ), chemical, mechanical,

• Some chemical treatment for REE study of bones; bones prepared mechanically

Primary reference: J. I. Kirkland, L. Zanno, D. Deblieux, D. Smith, and S. D. Sampson. 2004. A new, basal-most therizinosauroid (Theropoda: Maniraptora) from Utah demonstrates a pan-Laurasian distribution for Early Cretaceous (Barremian) therizinosauroids. Journal of Vertebrate Paleontology 24(3, suppl.):78A [M. Carrano/M. Carrano/M. Carrano]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 50052: authorized by Matthew Carrano, entered by Matthew Carrano on 05.05.2005

Creative Commons license: CC BY (attribution)

Taxonomic list

• Also present: polacanthine indet. fragments; theropod bone; turtle; croc teeth

Show authors, comments, and common names

Reptilia
Theropoda -	Theropoda indet.¹, Falcarius utahensis n. gen. n. sp.² Theropoda indet.¹ Marsh 1881 theropod Falcarius utahensis n. gen. n. sp.² Kirkland et al. 2005 coelurosaur MNI, perhaps actually hundreds in total
Ornithischia -	Ankylosauria indet.³ Ankylosauria indet.³ ankylosaur scutes
Ornithischia - Polacanthidae	Polacanthidae indet.¹ Polacanthidae indet.¹ Wieland 1911 ankylosaur
Crocodylia -	Crocodylia indet.¹ Crocodylia indet.¹ crocodilian Teeth

¹Kirkland and Madsen 2007; ²Kirkland et al. 2005; ³Suarez et al. 2007