Tomahawk locality, USNM 39981 (Triassic of the United States)

Also known as 1988-1

Where: Chesterfield County, Virginia (37.5° N, 77.7° W: paleocoordinates 2.4° N, 16.1° W)

• coordinate stated in text

• outcrop-level geographic resolution

When: Tomahawk Creek Member (Vinita Formation), Carnian (237.0 - 228.0 Ma)

• "Based on conchostracans, Kozur & Weems (2007) recently dated much of the succession in the Richmond Basin and correlative units in the adjacent Taylorsville basin as early Carnian (Cordevolian), but earlier Huber et al. (1993) had argued for a late Carnian age of these strata. At the present time this controversy cannot be resolved" (Sues & Hopson 2010)

•"Turkey Branch Formation" was previously used for this locality; Richmond Basin, Newark Supergroup

• bed-level stratigraphic resolution

Environment/lithology: lacustrine - small; silty, calcareous mudstone

• "shallow-wayer lacustrine origin"
• "massive calcareous mudstone, together with small (1-10 mm) carbonate nodules, poorly preserved root traces...At least two irregular layers of fissile, more silty mudstone extend within the massive mudstone"

Size classes: macrofossils, mesofossils, microfossils

Collected by Olsen, Sues in 1983, 1988-1992; reposited in the USNM

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

Primary reference: H.-D. Sues, P. E. Olsen, and P. A. Kroehler. 1994. Small tetrapods from the Upper Triassic of the Richmond basin (Newark Supergroup), Virginia. In the Shadow of the Dinosaurs: Early Mesozoic Tetrapods, N. C. Fraser and H.-D. Sues (eds.), Cambridge University Press 161-170 [M. Carrano/M. Carrano/M. Carrano]more details

Purpose of describing collection: general faunal/floral analysis

PaleoDB collection 39159: authorized by Matthew Carrano, entered by Matthew Carrano on 21.05.2004, edited by Patricia Holroyd

Creative Commons license: CC BY (attribution)

Taxonomic list

unclassified
  -
Gastropoda
  -
Gastropoda indet. Cuvier 1797 snail
Chondrichthyes
 Hybodontiformes - Lonchidiidae
Lissodus sp. Brough 1935 elasmobranch
Reptilia
 Procolophonia - Procolophonidae
Gomphiosauridion baileyae n. gen. n. sp.4
Gomphiosauridion baileyae n. gen. n. sp.4 Sues and Olsen 1993 parareptile
USNM 448630, partial maxilla
 Procolophonia -
Xenodiphyodon petraios n. gen. n. sp.4
Xenodiphyodon petraios n. gen. n. sp.4 Sues and Olsen 1993 parareptile
USNM 448631, partial dentary
 Eosuchia -
Uatchitodon kroehleri n. gen. n. sp.
Uatchitodon kroehleri n. gen. n. sp. Sues 1991 archosauromorph
USNM 448611 (holotype). USNM 448603-448, 610, 448621-448622, 448624, teeth
 Phytosauria -
"Parasuchia indet." = Phytosauria
"Parasuchia indet." = Phytosauria Jaeger 1828 archosaur
Isolated teeth
 Eosuchia -
Euscolosuchus olseni n. gen. n. sp.2 Sues 1992 archosauromorph
USNM 448587, associated osteoderms (holotype). USNM 448580-448586, 448588, 448589
Lepidosauria indet. Haeckel 1866 lepidosaur
 Rhynchocephalia -
Sphenodontia indet.3 rhynchocephalian
"similar to Diphydontosaurus"
Osteichthyes
 Therapsida -
Microconodon tenuirostris3 Osborn 1886 therapsid
USNM 437637, ROM 44300, 44301, partial dentaries, USNM 448579, 448600, ROM 44302, isolated teeth
Boreogomphodon jeffersoni n. gen. n. sp.3 Sues and Olsen 1990 therapsid
USNM 437632, left maxilla (holotype). CM 20050, 76800, 76801, 78803, USNM 437634, 437635, 437636, 448562, 448570, 448593, 448599, 448632, 448633, VMNH 3575, 3578, cranial remains. CM 76805, 76807, 76808, 76812, 76815, 76818, USNM 448563-448569, 448571-448573, 448575, 448576, 448578, 448597, 448601, 448625, 448629, isolated teeth. USNM 448602, 448598, VMNH 3577, postcranial elements
unclassified
  -
Pteridophyta indet. Haeckel 1875