Jim's Joy, Huizachal Canyon (Jurassic of Mexico)

Where: Tamaulipas, Mexico (26.6° N, 99.5° W: paleocoordinates 26.6° N, 99.5° W)

• coordinate based on nearby landmark

• outcrop-level geographic resolution

When: La Boca Formation, Pliensbachian (190.8 - 182.7 Ma)

• lower part of the La Boca Formation; originally dated as Middle Jurassic, but U-Pb isotopic data from zircon in a volcaniclastic rock from the lowest part of the formation yields an age of 189 plus/minus 0.2 Ma. The fossil-bearing sedimentary rocks are above this unit and conformable with it (see Montellano et al. 2008: JVP 28: 1130–1143).

• group of beds-level stratigraphic resolution

Environment/lithology: "floodplain"; lithology not reported

Size classes: macrofossils, mesofossils

Collection methods: IGM: Instituto de Geologia, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, Mexico

Primary reference: M. Montellano, J. A. Hopson, and J. M. Clark. 2008. Late Early Jurassic mammaliaforms from Huizachal Canyon, Tamaulipas, Mexico. Journal of Vertebrate Paleontology 28(4):1130-1143 [R. Butler/R. Butler]more details

Purpose of describing collection: taxonomic analysis

PaleoDB collection 136975: authorized by Richard Butler, entered by Richard Butler on 07.12.2012

Creative Commons license: CC BY (attribution)

Taxonomic list

 Rhynchocephalia - Sphenodontidae
Sphenovipera jimmysjoyi n. gen. n. sp.
Sphenovipera jimmysjoyi n. gen. n. sp. Reynoso 2005 rhynchocephalian
IGM 6076, right lower jaw (holotype)
 Therapsida -
Bocaconodon tamaulipensis n. gen. n. sp. Montellano et al. 2008 mammaliaform
"taxon A"