Coenholectypus bullardi Ikins, 1940
Plate: CoBu-10
Series: Upper Cretaceous Group: Austin Formation: Austin Chalk
Locale: Austin County: Travis Stage: Santonian
Length: 40.2 mm Height: 15.4 mm
Specimen in photo: Collection of Chris Garvie (The Akers Collection)
Repository: Private Collection
HOLOTYPE INFO:
Holotype: BEG 20530 (Syntypes) — Non-vertebrate Paleontology Laboratory, University of Texas (Ikins, 1940)
Locality: Little Walnut Creek, Austin, Travis County, Texas (Ikins, 1940)
Systematic Paleontology
CLASS: ECHINOIDEA Leske, 1778
SUBCLASS: EUECHINOIDEA Bronn, 1860
INFRACLASS: IRREGULARIA Latreille, 1825
SUPERORDER: GNATHOSTOMATA Zittel, 1879
ORDER: HOLECTYPOIDA Duncan, 1889
FAMILY: COENHOLECTYPIDAE Smith & Wright, 1999
GENUS: COENHOLECTYPUS Pomel, 1883
SPECIES: Coenholectypus bullardi (Ikins, 1940)
TYPE SPECIES: Discoidea depressa L. Agassiz, 1839
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Austin
Formations: Austin Chalk (Ikins, 1940)
Stratigraphic Units: Upper Cretaceous, Santonian
Counties: Travis County (Ikins, 1940)
DESCRIPTION
TOP: Length, height: 40.2 mm L × 15.4 mm H
Top shape: Circular, yet just slightly pentagonal ; Circular in outline (Ikins, 1940)
Top domed: Low, subconical (Ikins, 1940)
SIDE: Ambitus: 30% from bottom
Side shape: Sub-circular
BOTTOM: Bottom flat: Flat
AMB: Amb shape: Taper to point at apical disc; straight, widest at ambitus
Amb primary tubercles: Four rows of tubercles in amb; largest just above and below ambitus
Amb granules: Numerous
INTERAMB: Interamb width: 2.5 times wider than ambulacra
Interamb primary tubercles: Eight rows of tubercles; largest just above and below ambitus
Interamb granules: Numerous
PORE PAIRS: Shape: Round, small
Arrangement: Uniserial above, becoming a little offset below; tighter together above
TUBERCLES: Primary tubercles: Perforated, crenulated ; Small, perforated, crenulated (Ikins, 1940)
Density variation: Reduce in number approaching peristome and apical system
APICAL SYSTEM: Shape: Star pattern
Genital pores: 5 gonopores equally spaced with a central madreporite
PERIPROCT (ANUS): Shape & Size: Very large; both ends pointed, point more towards peristome ; Large, pyriform, acuminate adorally (Ikins, 1940)
Location: Infra-marginal (below ambitus), not seen from above; occupies all space between ambitus and just shy of peristome (Ikins, 1940)
PERISTOME (MOUTH): Size: Diameter 25% of test diameter
Shape: Oval ; Decagonal (Ikins, 1940)
Sunken: Depressed
Lip: Deep buccal notches with lips equal on amb and interamb sides ; Branchial incisions deep (Ikins, 1940)
SPECIMENS STUDIED & CONDITION
Specimen in Garvie Collection; Length 40.2 mm .
ETYMOLOGY: Named in honor of Fred M. Bullard (1901–1994), a geologist and professor at the University of Texas (Ikins, 1940).
REMARKS & COMPARISONS
Remarks: Ikins (1940) originally described this species as Holectypus bullardi, noting the infra-marginal periproct that occupies nearly the entire radius from the peristome to the posterior margin.
Comparisons: Ikins (1940) compares it to Holectypus limitis Böse, noting C. bullardi is larger, relatively lower, and has a smaller peristome.
Plate: CoBu-10
Series: Upper Cretaceous Group: Austin Formation: Austin Chalk
Locale: Austin County: Travis Stage: Santonian
Length: 40.2 mm Height: 15.4 mm
Specimen in photo: Collection of Chris Garvie (The Akers Collection)
Repository: Private Collection
HOLOTYPE INFO:
Holotype: BEG 20530 (Syntypes) — Non-vertebrate Paleontology Laboratory, University of Texas (Ikins, 1940)
Locality: Little Walnut Creek, Austin, Travis County, Texas (Ikins, 1940)
Systematic Paleontology
CLASS: ECHINOIDEA Leske, 1778
SUBCLASS: EUECHINOIDEA Bronn, 1860
INFRACLASS: IRREGULARIA Latreille, 1825
SUPERORDER: GNATHOSTOMATA Zittel, 1879
ORDER: HOLECTYPOIDA Duncan, 1889
FAMILY: COENHOLECTYPIDAE Smith & Wright, 1999
GENUS: COENHOLECTYPUS Pomel, 1883
SPECIES: Coenholectypus bullardi (Ikins, 1940)
TYPE SPECIES: Discoidea depressa L. Agassiz, 1839
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Austin
Formations: Austin Chalk (Ikins, 1940)
Stratigraphic Units: Upper Cretaceous, Santonian
Counties: Travis County (Ikins, 1940)
DESCRIPTION
TOP: Length, height: 40.2 mm L × 15.4 mm H
Top shape: Circular, yet just slightly pentagonal ; Circular in outline (Ikins, 1940)
Top domed: Low, subconical (Ikins, 1940)
SIDE: Ambitus: 30% from bottom
Side shape: Sub-circular
BOTTOM: Bottom flat: Flat
AMB: Amb shape: Taper to point at apical disc; straight, widest at ambitus
Amb primary tubercles: Four rows of tubercles in amb; largest just above and below ambitus
Amb granules: Numerous
INTERAMB: Interamb width: 2.5 times wider than ambulacra
Interamb primary tubercles: Eight rows of tubercles; largest just above and below ambitus
Interamb granules: Numerous
PORE PAIRS: Shape: Round, small
Arrangement: Uniserial above, becoming a little offset below; tighter together above
TUBERCLES: Primary tubercles: Perforated, crenulated ; Small, perforated, crenulated (Ikins, 1940)
Density variation: Reduce in number approaching peristome and apical system
APICAL SYSTEM: Shape: Star pattern
Genital pores: 5 gonopores equally spaced with a central madreporite
PERIPROCT (ANUS): Shape & Size: Very large; both ends pointed, point more towards peristome ; Large, pyriform, acuminate adorally (Ikins, 1940)
Location: Infra-marginal (below ambitus), not seen from above; occupies all space between ambitus and just shy of peristome (Ikins, 1940)
PERISTOME (MOUTH): Size: Diameter 25% of test diameter
Shape: Oval ; Decagonal (Ikins, 1940)
Sunken: Depressed
Lip: Deep buccal notches with lips equal on amb and interamb sides ; Branchial incisions deep (Ikins, 1940)
SPECIMENS STUDIED & CONDITION
Specimen in Garvie Collection; Length 40.2 mm .
ETYMOLOGY: Named in honor of Fred M. Bullard (1901–1994), a geologist and professor at the University of Texas (Ikins, 1940).
REMARKS & COMPARISONS
Remarks: Ikins (1940) originally described this species as Holectypus bullardi, noting the infra-marginal periproct that occupies nearly the entire radius from the peristome to the posterior margin.
Comparisons: Ikins (1940) compares it to Holectypus limitis Böse, noting C. bullardi is larger, relatively lower, and has a smaller peristome.
