Crassiholaster bexarensis Thompson, 2016
Plate: CrBe-10
Series: Upper Cretaceous Group: Austin Formation: Austin Chalk
Locale: San Antonio County: Bexar Stage: Santonian
Length: 62.0 mm Width: 60.1 mm Height: 47.0 mm
Specimen in photo: NPL 82990 (Holotype)
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: NPL 82990 — Non-vertebrate Paleontology Laboratory, University of Texas
Locality: San Antonio, Bexar County, Texas
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Irregularia Latreille, 1825
Superorder: Atelostomata Zittel, 1879
Order: Holasteroida Durham & Melville, 1957
Suborder: Meridosternata Lovén, 1883
Family: Holasteridae Pictet, 1857
Genus: CRASSIHOLASTER Smith & Wright, 2003
Species: Crassiholaster bexarensis Thompson, 2016
TYPE SPECIES: Spatangus subglobosus Leske, 1778
DIAGNOSIS
A Crassiholaster from the Austin Group, Upper Cretaceous of Texas, with a tall ovate test and a periproct that is almost circular .
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Austin
Formations: Austin Chalk
Stratigraphic Units: Upper Cretaceous, Santonian
Counties: Bexar County
DESCRIPTION
TOP: Length, width, height: 62.0 mm L × 60.1 mm W × 47.0 mm H
Top shape: Cordate, broad shoulders; faint anterior sulcus
Widest location: About 1/3rd from anterior end
SIDE: Ambitus: About 1/3rd from base
Side shape: Very inflated; backward sloping truncated posterior end; sloping anterior end
Apex: Above midpoint
BOTTOM: Bottom shape: Flat; curved below ambitus
AMB: Amb shape: Narrow, lanceolate, open ended
Amb primary zones: Anterior paired ambs widen near margin
PORE PAIRS: Shape: Most pores in paired ambs elongated, but some are round
TUBERCLES: Primary tubercles: More pronounced aborally, at margin on adoral side, and at plastron
Granules: Granulation more pronounced aborally and at plastron
APICAL SYSTEM: Size / Location: Small, central
Genital pores: 4 gonopores
PERIPROCT (ANUS): Shape & Size: Oval, slight point top and bottom
Location: On backward sloping truncated posterior end, below midpoint
Visibility: Can be seen from above
PERISTOME (MOUTH): Size: Smaller than periproct
Shape: Oval, subpentagonal; flat on bottom edge
Orientation: Facing anterior
Visibility: Can be seen from anterior end
SPECIMENS STUDIED & CONDITION
Specimen condition: Two specimens found; Holotype NPL 82990 .
ETYMOLOGY: Named after Bexar County .
REMARKS & COMPARISONS
Remarks: Crassiholaster bexarensis has a wider cordate shape than other Crassiholaster species. The periproct is more oval and the widest spot of the test is nearer to the anterior end than in Crassiholaster subglobosus and Crassiholaster sphaericus. .
Remarks (12/29/2025): Dan Woehr of San Antonio has found several specimens at one site in North San Antonio and led me to the site, where I found one. He also said small regulars come from the site, probably Gautheria parva.
Plate: CrBe-10
Series: Upper Cretaceous Group: Austin Formation: Austin Chalk
Locale: San Antonio County: Bexar Stage: Santonian
Length: 62.0 mm Width: 60.1 mm Height: 47.0 mm
Specimen in photo: NPL 82990 (Holotype)
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: NPL 82990 — Non-vertebrate Paleontology Laboratory, University of Texas
Locality: San Antonio, Bexar County, Texas
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Irregularia Latreille, 1825
Superorder: Atelostomata Zittel, 1879
Order: Holasteroida Durham & Melville, 1957
Suborder: Meridosternata Lovén, 1883
Family: Holasteridae Pictet, 1857
Genus: CRASSIHOLASTER Smith & Wright, 2003
Species: Crassiholaster bexarensis Thompson, 2016
TYPE SPECIES: Spatangus subglobosus Leske, 1778
DIAGNOSIS
A Crassiholaster from the Austin Group, Upper Cretaceous of Texas, with a tall ovate test and a periproct that is almost circular .
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Austin
Formations: Austin Chalk
Stratigraphic Units: Upper Cretaceous, Santonian
Counties: Bexar County
DESCRIPTION
TOP: Length, width, height: 62.0 mm L × 60.1 mm W × 47.0 mm H
Top shape: Cordate, broad shoulders; faint anterior sulcus
Widest location: About 1/3rd from anterior end
SIDE: Ambitus: About 1/3rd from base
Side shape: Very inflated; backward sloping truncated posterior end; sloping anterior end
Apex: Above midpoint
BOTTOM: Bottom shape: Flat; curved below ambitus
AMB: Amb shape: Narrow, lanceolate, open ended
Amb primary zones: Anterior paired ambs widen near margin
PORE PAIRS: Shape: Most pores in paired ambs elongated, but some are round
TUBERCLES: Primary tubercles: More pronounced aborally, at margin on adoral side, and at plastron
Granules: Granulation more pronounced aborally and at plastron
APICAL SYSTEM: Size / Location: Small, central
Genital pores: 4 gonopores
PERIPROCT (ANUS): Shape & Size: Oval, slight point top and bottom
Location: On backward sloping truncated posterior end, below midpoint
Visibility: Can be seen from above
PERISTOME (MOUTH): Size: Smaller than periproct
Shape: Oval, subpentagonal; flat on bottom edge
Orientation: Facing anterior
Visibility: Can be seen from anterior end
SPECIMENS STUDIED & CONDITION
Specimen condition: Two specimens found; Holotype NPL 82990 .
ETYMOLOGY: Named after Bexar County .
REMARKS & COMPARISONS
Remarks: Crassiholaster bexarensis has a wider cordate shape than other Crassiholaster species. The periproct is more oval and the widest spot of the test is nearer to the anterior end than in Crassiholaster subglobosus and Crassiholaster sphaericus. .
Remarks (12/29/2025): Dan Woehr of San Antonio has found several specimens at one site in North San Antonio and led me to the site, where I found one. He also said small regulars come from the site, probably Gautheria parva.
