Tetragramma streeruwitzi (Cragin, 1893)

Remarks

• Collector:     Lee Duchouquette

• Formation:   Basal Washita Group, Duck Creek Formation

• Location:      Tarrant County, TX

• Dimensions:  diam = 29 mm; ht = 10 mm

General Info

Synonyms (older names and misidentifications in the literature)

• 1893 Diplopodia streeruwitzi Cragin

• 1905 Diplopodia streeruvitzi Cragin; Clark & Twitchell

• 1910 Pseudodiadema (Diplopodia) cfr. variolare Brogniart; Böse

• 1915 Diplopodia streeruwitzi Cragin; Clark

• 1927 Tetragramma streeruwitzi (Cragin); Lambert

• 1928 Tetragramma streeruwitzi (Cragin); Adkins

• 1936 Tetragramma streeruwitzi (Cragin); Smiser

• 1946 Tetragramma streeruwitzi (Cragin); Cooke

• 1947 Tetragramma streeruwitzi (Cragin); Shimer & Shrock

• 1955 Tetragramma streeruwitzi (Cragin); Cooke

• 1987 Tetragramma streeruwitzi (Cragin); Akers & Akers

Stratigraphic Occurrence

• Washita Group, Grayson Formation of north Texas

• Washita Group, Weno Formation of north Texas

• Washita Group, Fort Worth Formation of north Texas

• Washita Group, Duck Creek Formation of north Texas

• Washita Group, Boracho Formation of Trans–Pecos Texas

• Washita Group, Smeltertown Formation of El Paso Texas

• Washita Group equivalent rocks of Chihuahua, Mexico (we believe it's the Espy Formation)

• Fredericksburg Group, Walnut Formation of North-Central Texas (specimen found by Lee Duchouquette)

Age

• Based on literature reports, Tetragramma  streeruwitzi  (Cragin) ranges from the Mortoniceras  equidistans  (Cragin) zone to the Graysonites  lozoi  Young zone, early Late Albian Stage to Early Cenomanian Stage (~101–97 mya).  One of Lee's echinoids from the Walnut extends its range down into the Middle Albian Stage.

Geographic Occurrence (by no means an all-inclusive list)

• Bell County, TX

• Chihuahua, Mexico

• Culberson County, TX

• El Paso County, TX

• Grayson County, TX

• Hudspeth County, TX

• Tarrant County, TX

Remarks

         For identification and descriptions, see:

• Clark, W. B.; Twitchell, M. W.  1915.  Mesozoic and Cenozoic Echinodermata of the United States.  United States Geological Survey Monograph 54.

• Cooke, C. W.  1946.  Comanche Echinoids.  Journal of Paleontology 20 (3), 193–237.