Pedinopsis texana Cooke, 1955
Plate: PeTe-10
Series: Lower Cretaceous Group: Washita Formation: Boracho
Locale: Kent County: Culbertson Stage: Cenomanian
Length: 17.1 mm Height: 12.5 mm
Specimen in photos: U.S.N.M. 469260
Paleobiology Depart. NMNH, Smithsonian Institution
Plate: PeTe-20
Series: Lower Cretaceous Group: Washita Formation: Mainstreet Limestone
Locale: Northlake County: Denton Stage: Cenomanian
Length: 31.0 mm Height: 18.3 mm
Repository: Private Collection
HOLOTYPE INFO:
Holotype: USNM 108704 (Cooke, 1955).
Locality: USGS 9691, Fort Worth, Tarrant County, Texas.
Stratigraphy: Main Street Limestone, Washita Group.
SYNONYMY
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Carinacea Kroh & Smith, 2010
Superorder: Calycina Gregory, 1900
Order: Phymosomatoida Mortensen, 1904
Family: Pedinopsidae Durham, 1955
Genus: PEDINOPSIS Cotteau, 1863
Species: Pedinopsis texana Cooke, 1955
TYPE SPECIES: Pedinopsis meridanensis Cotteau, 1863
DIAGNOSIS
Test hemispherical with a rounded margin. Ambulacra are nearly half as wide as interambulacra, with biserial pore zones throughout. Compound plates are sexigeminate (six pore pairs per plate). Tubercles are small, crenulate, and perforate, arranged in radial rows (Cooke, 1955).
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Washita
Formations: Main Street Limestone, Pawpaw Formation, Weno Clay, Boracho Formation.
Stratigraphic Units: Lower Cretaceous (Late Albian to Early Cenomanian).
Counties: Tarrant, Culberson, Denton.
Abundance: Uncommon.
DESCRIPTION
TOP: Length, width, height: 17.1 mm L × 12.5 mm H (PeTe-10); 31.0 mm L × 18.3 mm H (PeTe-20). Top shape: Horizontal outline subcircular. Top domed: Hemispherical profile.
SIDE: Side shape: Margin rounded.
AMB: Amb shape: Evenly expanding. Width: Nearly half as wide as the interambulacra. Amb arrangement: Tubercles arranged in two radial rows adjacent to the poriferous zones. Plating: Compound plates are half as high as wide, each with six pairs of pores (sexigeminate) in partial plates (Cooke, 1955).
PORE PAIRS: Arrangement: Biserial throughout; pore pairs alternate in location. Condition: Tending to be disarranged (crowded) at the peristome.
TUBERCLES: Primary Perforated: Yes. Primary Crenulate: Yes. Distribution: Small; slightly larger below the margin than elsewhere. Arranged in radial rows: two rows in ambulacra, six rows in interambulacra (with somewhat smaller tubercles intercalated).
GRANULES: Distribution: Intermediate areas are granular.
FASCIOLE: Absent.
INTERAMB: Shape: Plates are much wider than high and straight.
APICAL SYSTEM: Location: Central. Shape: Small and nearly circular scar (Cooke, 1955).
PERIPROCT (ANUS): (Unknown).
PERISTOME (MOUTH): Size: About one-quarter of the diameter. Shape: Circular. Lip: Weakly notched.
SPINES: Unknown.
SPECIMENS STUDIED & CONDITION:
ETYMOLOGY
Named for the state of Texas, the type locality.
REMARKS & COMPARISONS
Comparisons:
Plate: PeTe-10
Series: Lower Cretaceous Group: Washita Formation: Boracho
Locale: Kent County: Culbertson Stage: Cenomanian
Length: 17.1 mm Height: 12.5 mm
Specimen in photos: U.S.N.M. 469260
Paleobiology Depart. NMNH, Smithsonian Institution
Plate: PeTe-20
Series: Lower Cretaceous Group: Washita Formation: Mainstreet Limestone
Locale: Northlake County: Denton Stage: Cenomanian
Length: 31.0 mm Height: 18.3 mm
Repository: Private Collection
HOLOTYPE INFO:
Holotype: USNM 108704 (Cooke, 1955).
Locality: USGS 9691, Fort Worth, Tarrant County, Texas.
Stratigraphy: Main Street Limestone, Washita Group.
SYNONYMY
- Pedinopsis texana Cooke, 1955
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Carinacea Kroh & Smith, 2010
Superorder: Calycina Gregory, 1900
Order: Phymosomatoida Mortensen, 1904
Family: Pedinopsidae Durham, 1955
Genus: PEDINOPSIS Cotteau, 1863
Species: Pedinopsis texana Cooke, 1955
TYPE SPECIES: Pedinopsis meridanensis Cotteau, 1863
DIAGNOSIS
Test hemispherical with a rounded margin. Ambulacra are nearly half as wide as interambulacra, with biserial pore zones throughout. Compound plates are sexigeminate (six pore pairs per plate). Tubercles are small, crenulate, and perforate, arranged in radial rows (Cooke, 1955).
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Washita
Formations: Main Street Limestone, Pawpaw Formation, Weno Clay, Boracho Formation.
Stratigraphic Units: Lower Cretaceous (Late Albian to Early Cenomanian).
Counties: Tarrant, Culberson, Denton.
Abundance: Uncommon.
DESCRIPTION
TOP: Length, width, height: 17.1 mm L × 12.5 mm H (PeTe-10); 31.0 mm L × 18.3 mm H (PeTe-20). Top shape: Horizontal outline subcircular. Top domed: Hemispherical profile.
SIDE: Side shape: Margin rounded.
AMB: Amb shape: Evenly expanding. Width: Nearly half as wide as the interambulacra. Amb arrangement: Tubercles arranged in two radial rows adjacent to the poriferous zones. Plating: Compound plates are half as high as wide, each with six pairs of pores (sexigeminate) in partial plates (Cooke, 1955).
PORE PAIRS: Arrangement: Biserial throughout; pore pairs alternate in location. Condition: Tending to be disarranged (crowded) at the peristome.
TUBERCLES: Primary Perforated: Yes. Primary Crenulate: Yes. Distribution: Small; slightly larger below the margin than elsewhere. Arranged in radial rows: two rows in ambulacra, six rows in interambulacra (with somewhat smaller tubercles intercalated).
GRANULES: Distribution: Intermediate areas are granular.
FASCIOLE: Absent.
INTERAMB: Shape: Plates are much wider than high and straight.
APICAL SYSTEM: Location: Central. Shape: Small and nearly circular scar (Cooke, 1955).
PERIPROCT (ANUS): (Unknown).
PERISTOME (MOUTH): Size: About one-quarter of the diameter. Shape: Circular. Lip: Weakly notched.
SPINES: Unknown.
SPECIMENS STUDIED & CONDITION:
- Hypotype USNM 469260: Boracho Formation, Kent, Culberson County, TX.
- Specimen 2 (PeTe-20): Collection of Mike Doran. Main Street Limestone, Northlake, Denton County, TX. (Large specimen: 31.0 mm).
ETYMOLOGY
Named for the state of Texas, the type locality.
REMARKS & COMPARISONS
Comparisons:
- Pedinopsis meridanensis: P. texana resembles Cotteau's figures of the type species in general features but appears to have smaller tubercles above the margin (Cooke, 1955).
- Pedinopsis yarboroughi (syn. P. engerrandi): P. texana is much larger than these species from the Walnut Formation. P. yarboroughi has more rows of tubercles with an alignment that is dominantly transverse rather than radial (Cooke, 1955).
