Goniopygus bexarensis Thompson, 2020
Plate: GoBe-10
Series: Upper Cretaceous Group: Navarro Formation: Corsicana
Locale: San Antonio County: Bexar Stage: Maastrichtian
Length: 10.3 mm Width: 5.6 mm
Collection: Frank Crane
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: NPL 94329 — Non-vertebrate Paleontology Laboratory, University of Texas
Locality: Southwest Bexar County, Texas
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Carinacea Kroh & Smith, 2010
Superorder: Echinacea Claus, 1876
Order: Arbacioida Gregory, 1900
Family: Acropeltidae Lambert, 1911
Genus: GONIOPYGUS L. Agassiz, 1838
Species: Goniopygus bexarensis Thompson, 2020
TYPE SPECIES: Goniopygus major L. Agassiz, 1838
DIAGNOSIS
Similar to Goniopygus budaensis with larger genitals and broader oculars having fewer pustules and more ridges .
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Navarro
Formations: Corsicana Formation
Stratigraphic Units: Upper Cretaceous, Maastrichtian
Counties: Bexar County
DESCRIPTION
TOP: Length, width, height: 10.3 mm L × 5.6 mm H
Top shape: Round, slightly pentagonal from above
Top domed: Highly domed top; domed corona
SIDE: Ambitus: Just above adoral surface
Side shape: Inflated sides
BOTTOM: Flat bottom
AMB: Amb shape: Lanceolate; come to point at apical system, widest at ambitus, narrow slightly at peristome
Amb primary tubercles: Two rows of tubercles with large mamelons stagger between the two rows of pores
INTERAMB: Interamb width: Over 1.5 times wider than ambulacra
Interamb primary tubercles: Two rows of tubercles larger than ambulacral
Interamb plating: Plates wider than tall
PORE PAIRS: Shape: Round
Arrangement: Uniserial, trigeminate; become offset at peristome
TUBERCLES: Primary Perforated: No Imperforated
Primary Crenulate: Noncrenulate
Coverage: Tubercles cover entire test, excluding apical system and interradius
APICAL SYSTEM: Size: Large; occupies 68% of top of test
Shape: Sub-pentagonal, domed; spreading over edges of corona
Type: Dicyclic
Plates: Plates bumped and ridged. Oculars bird-shaped, ornamented with several ridges. Genitals ornamented with several ridges and a few tubercles.
PERIPROCT (ANUS): Shape & Size: Oval
Location: Central
PERISTOME (MOUTH): Size: Large; diameter 57% of base
Lip: Ten rounded notches with faint lips
SPINES: Unknown
SPECIMENS STUDIED & CONDITION: One specimen studied. Holotype NPL 94329.
ETYMOLOGY
This species is named for Bexar County from which it was found.
REMARKS & COMPARISONS
Remarks: Excluding the apical system and the larger tubercles on the adoral surface, this looks like Goniopygus budaensis. However, the apical cap is much larger in G. bexarensis. The genitals have fewer pustules and many ridges. The oculars have fewer pustules and many ridges and are more bird-shaped instead of block-shaped.
Plate: GoBe-10
Series: Upper Cretaceous Group: Navarro Formation: Corsicana
Locale: San Antonio County: Bexar Stage: Maastrichtian
Length: 10.3 mm Width: 5.6 mm
Collection: Frank Crane
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: NPL 94329 — Non-vertebrate Paleontology Laboratory, University of Texas
Locality: Southwest Bexar County, Texas
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Carinacea Kroh & Smith, 2010
Superorder: Echinacea Claus, 1876
Order: Arbacioida Gregory, 1900
Family: Acropeltidae Lambert, 1911
Genus: GONIOPYGUS L. Agassiz, 1838
Species: Goniopygus bexarensis Thompson, 2020
TYPE SPECIES: Goniopygus major L. Agassiz, 1838
DIAGNOSIS
Similar to Goniopygus budaensis with larger genitals and broader oculars having fewer pustules and more ridges .
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Navarro
Formations: Corsicana Formation
Stratigraphic Units: Upper Cretaceous, Maastrichtian
Counties: Bexar County
DESCRIPTION
TOP: Length, width, height: 10.3 mm L × 5.6 mm H
Top shape: Round, slightly pentagonal from above
Top domed: Highly domed top; domed corona
SIDE: Ambitus: Just above adoral surface
Side shape: Inflated sides
BOTTOM: Flat bottom
AMB: Amb shape: Lanceolate; come to point at apical system, widest at ambitus, narrow slightly at peristome
Amb primary tubercles: Two rows of tubercles with large mamelons stagger between the two rows of pores
INTERAMB: Interamb width: Over 1.5 times wider than ambulacra
Interamb primary tubercles: Two rows of tubercles larger than ambulacral
Interamb plating: Plates wider than tall
PORE PAIRS: Shape: Round
Arrangement: Uniserial, trigeminate; become offset at peristome
TUBERCLES: Primary Perforated: No Imperforated
Primary Crenulate: Noncrenulate
Coverage: Tubercles cover entire test, excluding apical system and interradius
APICAL SYSTEM: Size: Large; occupies 68% of top of test
Shape: Sub-pentagonal, domed; spreading over edges of corona
Type: Dicyclic
Plates: Plates bumped and ridged. Oculars bird-shaped, ornamented with several ridges. Genitals ornamented with several ridges and a few tubercles.
PERIPROCT (ANUS): Shape & Size: Oval
Location: Central
PERISTOME (MOUTH): Size: Large; diameter 57% of base
Lip: Ten rounded notches with faint lips
SPINES: Unknown
SPECIMENS STUDIED & CONDITION: One specimen studied. Holotype NPL 94329.
ETYMOLOGY
This species is named for Bexar County from which it was found.
REMARKS & COMPARISONS
Remarks: Excluding the apical system and the larger tubercles on the adoral surface, this looks like Goniopygus budaensis. However, the apical cap is much larger in G. bexarensis. The genitals have fewer pustules and many ridges. The oculars have fewer pustules and many ridges and are more bird-shaped instead of block-shaped.
