Anorthopygus texanus Cooke, 1946
Plate: AnTe-10
Series: Lower Cretaceous Group: Washita Formation: Boracho
Locale: Unknown County: Culberson Stage: Albian
Length: 33.3 mm Height: 19.2 mm
Specimen in photo: Collection of John Hinte
Repository: Private Collection
HOLOTYPE INFO:
Holotype: USNM 103902 — National Museum of Natural History, Smithsonian Institution (Cooke, 1946)
Locality: 3 miles southwest of Denison, Grayson County, Texas (Cooke, 1946)
Systematic Paleontology
CLASS: ECHINOIDEA Leske, 1778
SUBCLASS: EUECHINOIDEA Bronn, 1860
INFRACLASS: IRREGULARIA Latreille, 1825
SUPERORDER: GNATHOSTOMATA Zittel, 1879
ORDER: HOLECTYPOIDA Duncan, 1889
FAMILY: ANORTHOPYGIDAE Wagner & Durham, 1966
GENUS: ANORTHOPYGUS Cotteau, 1859
SPECIES: Anorthopygus texanus Cooke, 1946
TYPE SPECIES: Anorthopygus orbicularis (Grateloup, 1836)
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Washita (Cooke, 1946)
Formations: Boracho Formation ; Weno Limestone, Pawpaw Formation (Cooke, 1946)
Stratigraphic Units: Lower Cretaceous, Albian (Cooke, 1946)
Counties: Culberson ; Grayson, Tarrant (Cooke, 1946)
DESCRIPTION
TOP: Length, height: 33.3 mm × 19.2 mm ; Holotype: 32 mm L × 28.5 mm W × 18 mm H (Cooke, 1946)
Top shape: Test subhemispherical to slightly pentagonal; outline subcircular to subpentagonal (Cooke, 1946; Thompson, 2020)
Top domed: Top very globular ; strongly convex (Cooke, 1946)
Convexity: Highly inflated aborally (Cooke, 1946)
SIDE: Ambitus: Margin rounded with ambitus 1/3rd distance from adoral surface
Side shape: Inflated, globular
BOTTOM: Bottom flat: Oral surface flat (Cooke, 1946; Thompson, 2020)
Bottom shape: Flat to concave around peristome (Cooke, 1946)
AMB: Amb shape: Lanceolate, widest at ambitus, narrowing at peristome ; Narrow, straight (Cooke, 1946)
Amb primary tubercles: Tubercles reduced in size (Cooke, 1946)
Amb primary zones: Poriferous zones narrow (Cooke, 1946)
INTERAMB: Interamb width: 2.5 times wider than ambs at ambitus
Interamb plating: Plates very pronounced, wider than tall
Sutures: Interradial sutures very pronounced; perradial sutures pronounced
PORE PAIRS: Shape: Slightly elongated, uniserial, horizontal; slightly diagonal near peristome
Arrangement: Uniserial (Cooke, 1946; Thompson, 2020)
SUTURES: Primary Perforated: Yes (Thompson, 2020; Cooke, 1946)
Primary Crenulate: Yes (Cooke, 1946; Thompson, 2020)
Primary Areola shape: Sunken areole
TUBERCLES: Primary tubercles: Staggered, small, dense
Arrangement: Plates offset, staggered tubercles
APICAL SYSTEM: Size / Location: Central (Cooke, 1946; Thompson, 2020)
Genital pores: 4 genital plates with pores ; Ethmolytic, with 4 genital pores (Generic Definition, Smith 2020)
PERIPROCT (ANUS): Shape & Size: Large, oval (Cooke, 1946; Thompson, 2020)
Location: At margin, half above margin and half below ; Supramarginal, visible from above, occupying most of the posterior truncation (Cooke, 1946)
PERISTOME (MOUTH): Size: Diameter about 28% of diameter of test ; Large, about 1/3 diameter (Cooke, 1946)
Shape: Oval ; Decagonal (Cooke, 1946)
Lip: Notches weak ; Branchial slits deep (Cooke, 1946)
Sunken: Sunken
SPECIMENS STUDIED & CONDITION
Specimen condition: Specimen Length 33.3 mm .
SIZE:
REMARKS & COMPARISONS
Remarks: Anorthopygus texanus is distinguished by its supramarginal periproct (visible from the top), which separates it from the genus Holectypus (periproct on the bottom/infra-marginal) and Coenholectypus.
Comparisons: Cooke (1946) notes this species is very similar to Anorthopygus orbicularis (Grateloup) from the Cenomanian of France but is larger.
ETYMOLOGY: Named for the state of Texas, the origin of the holotype.
Plate: AnTe-10
Series: Lower Cretaceous Group: Washita Formation: Boracho
Locale: Unknown County: Culberson Stage: Albian
Length: 33.3 mm Height: 19.2 mm
Specimen in photo: Collection of John Hinte
Repository: Private Collection
HOLOTYPE INFO:
Holotype: USNM 103902 — National Museum of Natural History, Smithsonian Institution (Cooke, 1946)
Locality: 3 miles southwest of Denison, Grayson County, Texas (Cooke, 1946)
Systematic Paleontology
CLASS: ECHINOIDEA Leske, 1778
SUBCLASS: EUECHINOIDEA Bronn, 1860
INFRACLASS: IRREGULARIA Latreille, 1825
SUPERORDER: GNATHOSTOMATA Zittel, 1879
ORDER: HOLECTYPOIDA Duncan, 1889
FAMILY: ANORTHOPYGIDAE Wagner & Durham, 1966
GENUS: ANORTHOPYGUS Cotteau, 1859
SPECIES: Anorthopygus texanus Cooke, 1946
TYPE SPECIES: Anorthopygus orbicularis (Grateloup, 1836)
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Washita (Cooke, 1946)
Formations: Boracho Formation ; Weno Limestone, Pawpaw Formation (Cooke, 1946)
Stratigraphic Units: Lower Cretaceous, Albian (Cooke, 1946)
Counties: Culberson ; Grayson, Tarrant (Cooke, 1946)
DESCRIPTION
TOP: Length, height: 33.3 mm × 19.2 mm ; Holotype: 32 mm L × 28.5 mm W × 18 mm H (Cooke, 1946)
Top shape: Test subhemispherical to slightly pentagonal; outline subcircular to subpentagonal (Cooke, 1946; Thompson, 2020)
Top domed: Top very globular ; strongly convex (Cooke, 1946)
Convexity: Highly inflated aborally (Cooke, 1946)
SIDE: Ambitus: Margin rounded with ambitus 1/3rd distance from adoral surface
Side shape: Inflated, globular
BOTTOM: Bottom flat: Oral surface flat (Cooke, 1946; Thompson, 2020)
Bottom shape: Flat to concave around peristome (Cooke, 1946)
AMB: Amb shape: Lanceolate, widest at ambitus, narrowing at peristome ; Narrow, straight (Cooke, 1946)
Amb primary tubercles: Tubercles reduced in size (Cooke, 1946)
Amb primary zones: Poriferous zones narrow (Cooke, 1946)
INTERAMB: Interamb width: 2.5 times wider than ambs at ambitus
Interamb plating: Plates very pronounced, wider than tall
Sutures: Interradial sutures very pronounced; perradial sutures pronounced
PORE PAIRS: Shape: Slightly elongated, uniserial, horizontal; slightly diagonal near peristome
Arrangement: Uniserial (Cooke, 1946; Thompson, 2020)
SUTURES: Primary Perforated: Yes (Thompson, 2020; Cooke, 1946)
Primary Crenulate: Yes (Cooke, 1946; Thompson, 2020)
Primary Areola shape: Sunken areole
TUBERCLES: Primary tubercles: Staggered, small, dense
Arrangement: Plates offset, staggered tubercles
APICAL SYSTEM: Size / Location: Central (Cooke, 1946; Thompson, 2020)
Genital pores: 4 genital plates with pores ; Ethmolytic, with 4 genital pores (Generic Definition, Smith 2020)
PERIPROCT (ANUS): Shape & Size: Large, oval (Cooke, 1946; Thompson, 2020)
Location: At margin, half above margin and half below ; Supramarginal, visible from above, occupying most of the posterior truncation (Cooke, 1946)
PERISTOME (MOUTH): Size: Diameter about 28% of diameter of test ; Large, about 1/3 diameter (Cooke, 1946)
Shape: Oval ; Decagonal (Cooke, 1946)
Lip: Notches weak ; Branchial slits deep (Cooke, 1946)
Sunken: Sunken
SPECIMENS STUDIED & CONDITION
Specimen condition: Specimen Length 33.3 mm .
SIZE:
- Holotype Size: Length 35.2 mm (Cooke, 1946).
- Size Range: Length 20 mm to 36 mm (Akers & Akers, 1987).
- Average Size: Length ~28 mm.
- Largest Known: Length 35.2 mm (Cooke, 1946).
REMARKS & COMPARISONS
Remarks: Anorthopygus texanus is distinguished by its supramarginal periproct (visible from the top), which separates it from the genus Holectypus (periproct on the bottom/infra-marginal) and Coenholectypus.
Comparisons: Cooke (1946) notes this species is very similar to Anorthopygus orbicularis (Grateloup) from the Cenomanian of France but is larger.
ETYMOLOGY: Named for the state of Texas, the origin of the holotype.
