Coenholectypus hondoensis Cannon, in Ikins, 1940
Plate: CoHo-10
Series: Upper Cretaceous Group: Taylor Formation: Anacacho
Locale: Medina County: Bandera Stage: Campanian
Length: 11.3 mm Height: 5.7 mm Specimen in photo: MMNS IP-2501
Repository: Mississippi Museum of Natural Science
HOLOTYPE INFO:
Holotype: BEG 20531 (Syntypes) — Non-vertebrate Paleontology Laboratory, University of Texas (Ikins, 1940)
Locality: West bank of Hondo Creek, 1 mile south of the bridge, Bandera 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 hondoensis Cannon, in Ikins, 1940
TYPE SPECIES: Discoidea depressa L. Agassiz, 1839
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Taylor
Formations: Anacacho Limestone (Ikins, 1940)
Stratigraphic Units: Upper Cretaceous, Campanian
Counties: Bandera County (Ikins, 1940)
DESCRIPTION
TOP: Length, height: 11.3 mm L × 5.7 mm H
Top shape: Round, subpentagonal ; Circular to sub-pentagonal outline (Ikins, 1940)
Top domed: Sub-globular; low hemispherical to sub-conical (Ikins, 1940)
SIDE: Side shape: Sub-globular with flat bottom
BOTTOM: Bottom flat: Flat
AMB: Amb shape: Lanceolate
Amb primary zones: Uniserial; pores round, very small
INTERAMB: Interamb width: 2.2 times bigger than ambulacra
PORE PAIRS: Shape: Round, very small
TUBERCLES: Primary tubercles: Perforated, finely crenulate; Small, crenulate, perforated (Ikins, 1940)
APICAL SYSTEM: Size / Location: Very small; Central (Ikins, 1940)
Genital pores: 5 gonopores
PERIPROCT (ANUS): Shape & Size: Oval, rounded on both ends, length longer than width; Small to medium size, pyriform (Ikins, 1940)
Location: Infra-marginal (on bottom), covers half of area from ambitus to peristome; cannot be seen from top or side
PERISTOME (MOUTH): Size: Diameter 20% of diameter test
Shape: Slightly ovate ; Decagonal (Ikins, 1940)
SPECIMENS STUDIED & CONDITION: Specimen MMNS IP-2501 .
ETYMOLOGY: Named for Hondo Creek (Bandera County), the type locality (Cannon/Ikins, 1940).
REMARKS & COMPARISONS
Remarks: This species was originally described as Holectypus hondoensis by Cannon in Ikins (1940). It is distinguished by its small size (typically <15mm) and infra-marginal periproct.
Plate: CoHo-10
Series: Upper Cretaceous Group: Taylor Formation: Anacacho
Locale: Medina County: Bandera Stage: Campanian
Length: 11.3 mm Height: 5.7 mm Specimen in photo: MMNS IP-2501
Repository: Mississippi Museum of Natural Science
HOLOTYPE INFO:
Holotype: BEG 20531 (Syntypes) — Non-vertebrate Paleontology Laboratory, University of Texas (Ikins, 1940)
Locality: West bank of Hondo Creek, 1 mile south of the bridge, Bandera 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 hondoensis Cannon, in Ikins, 1940
TYPE SPECIES: Discoidea depressa L. Agassiz, 1839
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Taylor
Formations: Anacacho Limestone (Ikins, 1940)
Stratigraphic Units: Upper Cretaceous, Campanian
Counties: Bandera County (Ikins, 1940)
DESCRIPTION
TOP: Length, height: 11.3 mm L × 5.7 mm H
Top shape: Round, subpentagonal ; Circular to sub-pentagonal outline (Ikins, 1940)
Top domed: Sub-globular; low hemispherical to sub-conical (Ikins, 1940)
SIDE: Side shape: Sub-globular with flat bottom
BOTTOM: Bottom flat: Flat
AMB: Amb shape: Lanceolate
Amb primary zones: Uniserial; pores round, very small
INTERAMB: Interamb width: 2.2 times bigger than ambulacra
PORE PAIRS: Shape: Round, very small
TUBERCLES: Primary tubercles: Perforated, finely crenulate; Small, crenulate, perforated (Ikins, 1940)
APICAL SYSTEM: Size / Location: Very small; Central (Ikins, 1940)
Genital pores: 5 gonopores
PERIPROCT (ANUS): Shape & Size: Oval, rounded on both ends, length longer than width; Small to medium size, pyriform (Ikins, 1940)
Location: Infra-marginal (on bottom), covers half of area from ambitus to peristome; cannot be seen from top or side
PERISTOME (MOUTH): Size: Diameter 20% of diameter test
Shape: Slightly ovate ; Decagonal (Ikins, 1940)
SPECIMENS STUDIED & CONDITION: Specimen MMNS IP-2501 .
ETYMOLOGY: Named for Hondo Creek (Bandera County), the type locality (Cannon/Ikins, 1940).
REMARKS & COMPARISONS
Remarks: This species was originally described as Holectypus hondoensis by Cannon in Ikins (1940). It is distinguished by its small size (typically <15mm) and infra-marginal periproct.
