Temnocidaris (Stereocidaris) hudspethensis Cooke, 1955
Plate: TesHu-10
Series: Upper Cretaceous Group: Washita Formation: Georgetown
Locale: Georgetown County: Williamson Stage: Albian
Length: 71.2 mm Height: 56.0 mm
Specimen in photos: Collection of Danny Harlow
Plate: TesHu-20
Series: Lower Cretaceous Group: Washita Formation: Duck Creek
Locale: Lake Texoma County: Grayson Stage: Albian
Length: 80 mm Height: 78 mm
Specimen in photos: Collection of Frank Crane
Plate: TesHu-30
Series: Upper Cretaceous Group: Washita Formation: Boracho
Locale: (private property) County: Hudspeth Stage: Cenomanian
Length: 74 mm Diameter: 10 mm
Specimen in photos: Collection of Frank Crane Spines
Repository: Private Collections
HOLOTYPE INFO:
Holotype: USNM 108697 (Cooke, 1955).
Locality: USGS 1938, 5 miles west of Kent, Culberson County, Texas.
Stratigraphy: Washita Group.
SYNONYMY
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Cidaroidea Smith, 1984
Order: Cidaroida Claus, 1880
Family: Cidaridae Gray, 1825
Genus: TEMNOCIDARIS Cotteau, 1863
Subgenus: STEREOCIDARIS Pomel, 1883
Species: Temnocidaris (Stereocidaris) hudspethensis Cooke, 1955
TYPE SPECIES: Cidaris cretosa Mantell, 1822 (for Temnocidaris); Cidaris merceyi Cotteau, 1857 (for Stereocidaris)
DIAGNOSIS
A large Stereocidaris characterized by strongly sinuous ambulacra. Ambulacral plates possess one large, elongated wart and one outer granule. Upper interambulacral plates feature rudimentary tubercles (small tubercle without areole or none). Distinguished from P. hemigranosus by the ambulacral ornamentation and finer general sculpture (Cooke, 1955).
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Washita
Formations: Georgetown Formation, Duck Creek Formation, Boracho Formation.
Stratigraphic Units: Lower Cretaceous (Albian) to Upper Cretaceous (Cenomanian).
Counties: Williamson, Grayson, Hudspeth, Culberson.
Abundance: Uncommon; often found as large tests or associated spines.
DESCRIPTION
TOP: Length, width, height: 71.2 mm L × 56.0 mm H (TesHu-10). Top shape: Circular. Top domed: Oblate-spheroidal.
AMB: Amb shape: Narrow, ribbon-like, and strongly sinuous. Amb arrangement: Interporiferous zones feature one large, elongated wart and one outer granule on each plate (Diagnostic).
PORE PAIRS: Arrangement: Conjugate and oblique. Poriferous zones are half as wide as the interporiferous zones.
TUBERCLES: Primary Perforated: Yes. Primary Crenulate: No (Bosses smooth). Interambulacral Tubercles: Five tiers of coronal plates. Tubercles are large, smooth, and central on lower plates. Highest tier (adapical) has rudimentary tubercles: large plates have one small tubercle without an areole; small plates have none.
GRANULES: Distribution: Miliary spaces covered with close-set rounded warts. Rows of granules present along the sutures.
FASCIOLE: Absent in Cidaroida.
INTERAMB: Arrangement: Separated by conspicuous sutures.
APICAL SYSTEM: Size: Moderately large. Plating: Five perforated genital plates and five nearly insert ocular plates. Ornamentation: Covered by large warts and granules.
PERIPROCT (ANUS): Shape: Pentagonal and large. Location: Central within the apical system.
PERISTOME (MOUTH): Shape: Circular. Size: Nearly one-third the horizontal diameter.
LANTERN: Teeth strong.
SPINES: Shape: Cylindrical. Ornamentation: Fluted.
SPECIMENS STUDIED & CONDITION:
ETYMOLOGY
Named for Hudspeth County, Texas (or the Hudspeth cutoff near the type locality in adjacent Culberson County).
REMARKS & COMPARISONS
Remarks: This species was historically misidentified as Cidaris hemigranosus Shumard by Clark (1915). Cooke (1955) corrected this, noting that Clark's description of hemigranosus (small peristome, fine sculpture) actually matched hudspethensis.
Comparisons:
Plate: TesHu-10
Series: Upper Cretaceous Group: Washita Formation: Georgetown
Locale: Georgetown County: Williamson Stage: Albian
Length: 71.2 mm Height: 56.0 mm
Specimen in photos: Collection of Danny Harlow
Plate: TesHu-20
Series: Lower Cretaceous Group: Washita Formation: Duck Creek
Locale: Lake Texoma County: Grayson Stage: Albian
Length: 80 mm Height: 78 mm
Specimen in photos: Collection of Frank Crane
Plate: TesHu-30
Series: Upper Cretaceous Group: Washita Formation: Boracho
Locale: (private property) County: Hudspeth Stage: Cenomanian
Length: 74 mm Diameter: 10 mm
Specimen in photos: Collection of Frank Crane Spines
Repository: Private Collections
HOLOTYPE INFO:
Holotype: USNM 108697 (Cooke, 1955).
Locality: USGS 1938, 5 miles west of Kent, Culberson County, Texas.
Stratigraphy: Washita Group.
SYNONYMY
- Stereocidaris hudspethensis Cooke, 1955
- Leiocidaris hemigranosus (Shumard) (fide Clark, 1915; misidentification corrected by Cooke, 1955)
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Cidaroidea Smith, 1984
Order: Cidaroida Claus, 1880
Family: Cidaridae Gray, 1825
Genus: TEMNOCIDARIS Cotteau, 1863
Subgenus: STEREOCIDARIS Pomel, 1883
Species: Temnocidaris (Stereocidaris) hudspethensis Cooke, 1955
TYPE SPECIES: Cidaris cretosa Mantell, 1822 (for Temnocidaris); Cidaris merceyi Cotteau, 1857 (for Stereocidaris)
DIAGNOSIS
A large Stereocidaris characterized by strongly sinuous ambulacra. Ambulacral plates possess one large, elongated wart and one outer granule. Upper interambulacral plates feature rudimentary tubercles (small tubercle without areole or none). Distinguished from P. hemigranosus by the ambulacral ornamentation and finer general sculpture (Cooke, 1955).
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Washita
Formations: Georgetown Formation, Duck Creek Formation, Boracho Formation.
Stratigraphic Units: Lower Cretaceous (Albian) to Upper Cretaceous (Cenomanian).
Counties: Williamson, Grayson, Hudspeth, Culberson.
Abundance: Uncommon; often found as large tests or associated spines.
DESCRIPTION
TOP: Length, width, height: 71.2 mm L × 56.0 mm H (TesHu-10). Top shape: Circular. Top domed: Oblate-spheroidal.
AMB: Amb shape: Narrow, ribbon-like, and strongly sinuous. Amb arrangement: Interporiferous zones feature one large, elongated wart and one outer granule on each plate (Diagnostic).
PORE PAIRS: Arrangement: Conjugate and oblique. Poriferous zones are half as wide as the interporiferous zones.
TUBERCLES: Primary Perforated: Yes. Primary Crenulate: No (Bosses smooth). Interambulacral Tubercles: Five tiers of coronal plates. Tubercles are large, smooth, and central on lower plates. Highest tier (adapical) has rudimentary tubercles: large plates have one small tubercle without an areole; small plates have none.
GRANULES: Distribution: Miliary spaces covered with close-set rounded warts. Rows of granules present along the sutures.
FASCIOLE: Absent in Cidaroida.
INTERAMB: Arrangement: Separated by conspicuous sutures.
APICAL SYSTEM: Size: Moderately large. Plating: Five perforated genital plates and five nearly insert ocular plates. Ornamentation: Covered by large warts and granules.
PERIPROCT (ANUS): Shape: Pentagonal and large. Location: Central within the apical system.
PERISTOME (MOUTH): Shape: Circular. Size: Nearly one-third the horizontal diameter.
LANTERN: Teeth strong.
SPINES: Shape: Cylindrical. Ornamentation: Fluted.
SPECIMENS STUDIED & CONDITION:
- TesHu-10: Georgetown Fm, Williamson Co. (Danny Harlow).
- TesHu-20: Duck Creek Fm, Grayson Co. (Frank Crane). Large specimen (80 mm).
- TesHu-30: Boracho Fm, Hudspeth Co. (Frank Crane). Spines.
ETYMOLOGY
Named for Hudspeth County, Texas (or the Hudspeth cutoff near the type locality in adjacent Culberson County).
REMARKS & COMPARISONS
Remarks: This species was historically misidentified as Cidaris hemigranosus Shumard by Clark (1915). Cooke (1955) corrected this, noting that Clark's description of hemigranosus (small peristome, fine sculpture) actually matched hudspethensis.
Comparisons:
- Phyllacanthus hemigranosus: T. (S.) hudspethensis is distinguished by the ambulacral ornamentation. P. hemigranosus features an elongated trough between pore pairs followed by a large tubercle and multiple random smaller tubercles (or 6 rows of granules per Clark), whereas T. (S.) hudspethensis has a strict pattern of one large elongated wart and one outer granule.
- Stereocidaris cretosa: T. (S.) hudspethensis is about twice as large as S. cretosa, with coarser decoration (more warts, fewer granules) and more flexuous ambulacra (Cooke, 1955).
