Temnholectypus castilloi (Cotteau, 1890)
Plate: TeCa-10
Series: Lower Cretaceous Group: Washita Formation: Georgetown
Locale: Del Rio County: Val Verde Stage: Albian
Length: 47.6 mm Height: 21.0 mm
Specimen in photo: U.S.N.M. 108718 Hypotype
Collection: Paleobiology Depart. NMNH, Smithsonian Institution
Collector: USGS SURVEY
Repository: Paleobiology Dept., NMNH, Smithsonian Institution
HOLOTYPE INFO:
Holotype: Cotteau Collection (Location uncertain, possibly MNHN Paris or destroyed).
Locality: Jalpa, Jalisco, Mexico.
Stratigraphy: Cretaceous (Albian/Cenomanian).
SYNONYMY
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Irregularia Latreille, 1825
Superorder: Holectypoida Ducrotay de Blainville, 1825
Order: Holectypoida Ducrotay de Blainville, 1825
Family: Holectypidae Lambert, 1900
Genus: TEMNHOLECTYPUS Lambert, 1918
Species: Temnholectypus castilloi (Cotteau, 1890)
TYPE SPECIES: Holectypus macropygus Desor, 1842
DIAGNOSIS
Test large, subpentagonal to circular, and low-arched. Apical system has five perforated genital plates. Periproct is inframarginal, pyriform, and situated closer to the posterior margin than to the peristome (separated from the peristome by 3 to 4 interambulacral plates). Distinguished from C. planatus by the smaller, more marginal periproct and smaller peristome.
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Washita
Formations: Georgetown Formation; Main Street Limestone; Escondido Formation (Mexico).
Stratigraphic Units: Lower Cretaceous, Albian.
Counties: Val Verde, Grayson.
Abundance: Uncommon in Texas; common in Mexico.
DESCRIPTION
TOP: Length, width, height: 47.6 mm L × 21.0 mm H (Hypotype). Top shape: Subpentagonal to circular (Cooke, 1955); quinquelateral-round (Cragin, 1893). Top domed: Low-arched above; superior slopes convex. Apex tends to rise slightly from a somewhat flattened summit region (Cragin, 1893).
SIDE: Side shape: Less elevated than C. planatus (Cragin, 1893).
BOTTOM: Bottom shape: Concave below (Cooke, 1955).
AMB: Amb shape: Straight; narrow. Amb arrangement: About one-third as large as the interambulacra (Cooke, 1955).
PORE PAIRS: Arrangement: Poriferous zones continuous and narrow. Pore pairs slightly oblique on top, more strongly oblique on bottom (Cooke, 1953). Shape: Outer pores larger, more elongated, and more transversely oblique than inner pores (Cragin, 1893). Features: Pores separated by a high partition.
TUBERCLES: Distribution: Arranged in concentric circles. Small on upper surface; much larger, perforated, and crenulated on lower surface (Cooke, 1955).
GRANULES: See Tubercles.
FASCIOLE: Absent in Holectypoida.
APICAL SYSTEM: Location: Central. Genital pores: Five perforated genital plates (Diagnostic for Coenholectypus/Temnholectypus group). Plating: Ocular plates about as large as the genitals; inserted against the large central madreporite. Madreporite is large and irregularly bounded, tending to present a short lobe opposite each ocular plate (Cragin, 1893).
PERIPROCT (ANUS): Shape: Subovate/Pyriform; centipetally rounded and centrifugally narrower and pointed (Cragin, 1893). Location: Inframarginal (on the bottom) but widely separated from the peristome; occupies less than one-third the space between peristome and margin; closer to the margin.
PERISTOME (MOUTH): Shape: Nearly circular or subpentagonal; strongly notched. Size: Small; about 8.2 mm in a 63 mm test (Cragin, 1893). Location: Central.
SPINES: Shape: Slender, longitudinally ribbed (Cooke, 1955).
SPECIMENS STUDIED & CONDITION: Hypotype USNM 108718. Note: Cragin (1893) described a larger specimen (63 mm) as Holectypus charltoni.
ETYMOLOGY
Named in honor of Antonio del Castillo (1820–1895), a prominent Mexican geologist.
REMARKS & COMPARISONS
Remarks: This species is assigned to Temnholectypus (often treated as a subgenus of Coenholectypus) based on the position of the periproct. In Coenholectypus sensu stricto (e.g., C. planatus), the periproct is very large and extends close to the peristome. In Temnholectypus, the periproct is marginal/inframarginal and separated from the peristome by 3 to 4 interambulacral plates (Book Author). Smith & Kroh (2011) list charltoni as a synonym of castilloi.
Comparisons:
Plate: TeCa-10
Series: Lower Cretaceous Group: Washita Formation: Georgetown
Locale: Del Rio County: Val Verde Stage: Albian
Length: 47.6 mm Height: 21.0 mm
Specimen in photo: U.S.N.M. 108718 Hypotype
Collection: Paleobiology Depart. NMNH, Smithsonian Institution
Collector: USGS SURVEY
Repository: Paleobiology Dept., NMNH, Smithsonian Institution
HOLOTYPE INFO:
Holotype: Cotteau Collection (Location uncertain, possibly MNHN Paris or destroyed).
Locality: Jalpa, Jalisco, Mexico.
Stratigraphy: Cretaceous (Albian/Cenomanian).
SYNONYMY
- Holectypus castilloi Cotteau, 1890
- Holectypus charltoni Cragin, 1893
- Coenholectypus castilloi (Cotteau) Cooke, 1955
- Caenholectypus (Temnholectypus) castilloi (Cotteau)
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Irregularia Latreille, 1825
Superorder: Holectypoida Ducrotay de Blainville, 1825
Order: Holectypoida Ducrotay de Blainville, 1825
Family: Holectypidae Lambert, 1900
Genus: TEMNHOLECTYPUS Lambert, 1918
Species: Temnholectypus castilloi (Cotteau, 1890)
TYPE SPECIES: Holectypus macropygus Desor, 1842
DIAGNOSIS
Test large, subpentagonal to circular, and low-arched. Apical system has five perforated genital plates. Periproct is inframarginal, pyriform, and situated closer to the posterior margin than to the peristome (separated from the peristome by 3 to 4 interambulacral plates). Distinguished from C. planatus by the smaller, more marginal periproct and smaller peristome.
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Washita
Formations: Georgetown Formation; Main Street Limestone; Escondido Formation (Mexico).
Stratigraphic Units: Lower Cretaceous, Albian.
Counties: Val Verde, Grayson.
Abundance: Uncommon in Texas; common in Mexico.
DESCRIPTION
TOP: Length, width, height: 47.6 mm L × 21.0 mm H (Hypotype). Top shape: Subpentagonal to circular (Cooke, 1955); quinquelateral-round (Cragin, 1893). Top domed: Low-arched above; superior slopes convex. Apex tends to rise slightly from a somewhat flattened summit region (Cragin, 1893).
SIDE: Side shape: Less elevated than C. planatus (Cragin, 1893).
BOTTOM: Bottom shape: Concave below (Cooke, 1955).
AMB: Amb shape: Straight; narrow. Amb arrangement: About one-third as large as the interambulacra (Cooke, 1955).
PORE PAIRS: Arrangement: Poriferous zones continuous and narrow. Pore pairs slightly oblique on top, more strongly oblique on bottom (Cooke, 1953). Shape: Outer pores larger, more elongated, and more transversely oblique than inner pores (Cragin, 1893). Features: Pores separated by a high partition.
TUBERCLES: Distribution: Arranged in concentric circles. Small on upper surface; much larger, perforated, and crenulated on lower surface (Cooke, 1955).
GRANULES: See Tubercles.
FASCIOLE: Absent in Holectypoida.
APICAL SYSTEM: Location: Central. Genital pores: Five perforated genital plates (Diagnostic for Coenholectypus/Temnholectypus group). Plating: Ocular plates about as large as the genitals; inserted against the large central madreporite. Madreporite is large and irregularly bounded, tending to present a short lobe opposite each ocular plate (Cragin, 1893).
PERIPROCT (ANUS): Shape: Subovate/Pyriform; centipetally rounded and centrifugally narrower and pointed (Cragin, 1893). Location: Inframarginal (on the bottom) but widely separated from the peristome; occupies less than one-third the space between peristome and margin; closer to the margin.
PERISTOME (MOUTH): Shape: Nearly circular or subpentagonal; strongly notched. Size: Small; about 8.2 mm in a 63 mm test (Cragin, 1893). Location: Central.
SPINES: Shape: Slender, longitudinally ribbed (Cooke, 1955).
SPECIMENS STUDIED & CONDITION: Hypotype USNM 108718. Note: Cragin (1893) described a larger specimen (63 mm) as Holectypus charltoni.
ETYMOLOGY
Named in honor of Antonio del Castillo (1820–1895), a prominent Mexican geologist.
REMARKS & COMPARISONS
Remarks: This species is assigned to Temnholectypus (often treated as a subgenus of Coenholectypus) based on the position of the periproct. In Coenholectypus sensu stricto (e.g., C. planatus), the periproct is very large and extends close to the peristome. In Temnholectypus, the periproct is marginal/inframarginal and separated from the peristome by 3 to 4 interambulacral plates (Book Author). Smith & Kroh (2011) list charltoni as a synonym of castilloi.
Comparisons:
- Coenholectypus planatus: T. castilloi has a smaller, more circular peristome, a much smaller periproct located further from the mouth, narrower ambulacra, and generally larger test size (Cooke, 1955; Cragin, 1893).
- Coenholectypus transpecosensis: The peristome of T. castilloi is smaller than that of C. transpecosensis, and the periproct is nearer the margin (Cooke, 1955).
