Salenia scotti Ikins, 1940
Plate: SaSc-10
Series: Lower Cretaceous Group: Fredericksburg Formation: Goodland
Locale: Fort Worth County: Tarrant Stage: Albian
Length: 16.0 mm Height: more than 10.6 mm (damaged)
Collector: Sharla Rainer
Specimen: NPL 94361
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
Plate: SaSc-20
Series: Lower Cretaceous Group: Washita Formation: Weno
Locale: Fort Worth County: Tarrant Stage: Albian
Length: 17.0 mm Height: 12.5
Collector: Scott Taylor
Specimen NPL 94362
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: UT Collection (Ikins, 1940).
Locality: Unknown (Ikins, 1940).
Stratigraphy: Upper Salenia level of the Goodland Formation (Fredericksburg Group).
SYNONYMY
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Carinacea Kroh & Smith, 2010
Superorder: Calycina Gregory, 1900
Order: Salenioida Delage & Hérouard, 1903
Family: Saleniidae L. Agassiz, 1838
Genus: SALENIA Gray, 1835
Species: Salenia scotti Ikins, 1940
TYPE SPECIES: Cidaris scutigera Gray, 1835
DIAGNOSIS
Test subcircular and greatly elevated. Apical system is large with characteristic ornamentation consisting of radiating furrows (finger-shaped pits) extending from the suranal plate. Ambulacral tubercles number approximately 19 to 24. Distinguished from S. mexicana by its greater elevation and unique apical ornamentation (Ikins, 1940).
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Fredericksburg; Washita.
Formations: Goodland Limestone (Type); Fort Worth Limestone, Weno Formation (Specimens).
Stratigraphic Units: Lower Cretaceous, Albian.
Counties: Tarrant.
Abundance: Uncommon.
DESCRIPTION
TOP: Length, width, height: 16.0–17.0 mm L × 12.5 mm H. Top shape: Subcircular in ambital outline. Top domed: Greatly elevated; apical system sits raised on the corona.
SIDE: Side shape: Sides slightly inflated; slope from apex to the ambitus.
BOTTOM: Bottom shape: Adactinal surface flat (Ikins, 1940); concave to peristome (Book Author).
AMB: Amb shape: Straight and narrow; lanceolate. Widest at the peristome. Amb arrangement: Surface ornamented with two rows of alternating tubercles (19 per Ikins; 24 per Book Author).
PORE PAIRS: Arrangement: Uniserial; becoming more numerous and irregular/crowded upon approaching the peristome. Elements: Bigeminate.
TUBERCLES: Primary Perforated: No (Imperforate). Primary Crenulate: Yes. Ambulacral Tubercles: Alternating, imperforate, mammillated, and circular. Rows of fine granulation between tubercles at perradial sutures. Interambulacral Tubercles: Two rows of large alternating plates (staggered); six plates per row. Tubercles are largest at the ambitus and above.
GRANULES: Distribution: In interambulacra: two granules in the upper adradial corner, one in the lower adradial corner, and four on the medial margin of plates (Ikins, 1940). Book Author notes bands of granules along the interradial suture running to the apical cap.
FASCIOLE: Absent.
APICAL SYSTEM: Size: Large; diameter about 61% of test. Shape: Circular to subpentagonal. Plating: Oculars are "bird-shaped with legs" (Book Author) or triangular (Ikins, 1940). Suranal plate is smaller than periproct. Genital plates have a central gonopore. Ornamentation: Highly characteristic; radiating furrows extend from the suranal plate. Genital plates feature 9 very pronounced long finger-shaped suture pits.
PERIPROCT (ANUS): Shape: Triangular or deltoid (Ikins, 1940); subpentagonal (Book Author). Location: More central to the apical system; elevated.
PERISTOME (MOUTH): Size: Large; about one-half the diameter of the test. Shape: Circular. Lip: Ten greatly developed branchial incisions.
SPINES: Unknown.
SPECIMENS STUDIED & CONDITION:
ETYMOLOGY
Named in honor of Gayle Scott (1894–1948), Professor of Geology at Texas Christian University and authority on Texas Cretaceous paleontology.
REMARKS & COMPARISONS
Remarks: The apical system's radiating finger-shaped suture pits resemble Salenia elliotti, but S. scotti has fewer pits on each genital plate.
Comparisons:
Plate: SaSc-10
Series: Lower Cretaceous Group: Fredericksburg Formation: Goodland
Locale: Fort Worth County: Tarrant Stage: Albian
Length: 16.0 mm Height: more than 10.6 mm (damaged)
Collector: Sharla Rainer
Specimen: NPL 94361
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
Plate: SaSc-20
Series: Lower Cretaceous Group: Washita Formation: Weno
Locale: Fort Worth County: Tarrant Stage: Albian
Length: 17.0 mm Height: 12.5
Collector: Scott Taylor
Specimen NPL 94362
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: UT Collection (Ikins, 1940).
Locality: Unknown (Ikins, 1940).
Stratigraphy: Upper Salenia level of the Goodland Formation (Fredericksburg Group).
SYNONYMY
- Salenia scotti Ikins, 1940
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Carinacea Kroh & Smith, 2010
Superorder: Calycina Gregory, 1900
Order: Salenioida Delage & Hérouard, 1903
Family: Saleniidae L. Agassiz, 1838
Genus: SALENIA Gray, 1835
Species: Salenia scotti Ikins, 1940
TYPE SPECIES: Cidaris scutigera Gray, 1835
DIAGNOSIS
Test subcircular and greatly elevated. Apical system is large with characteristic ornamentation consisting of radiating furrows (finger-shaped pits) extending from the suranal plate. Ambulacral tubercles number approximately 19 to 24. Distinguished from S. mexicana by its greater elevation and unique apical ornamentation (Ikins, 1940).
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Fredericksburg; Washita.
Formations: Goodland Limestone (Type); Fort Worth Limestone, Weno Formation (Specimens).
Stratigraphic Units: Lower Cretaceous, Albian.
Counties: Tarrant.
Abundance: Uncommon.
DESCRIPTION
TOP: Length, width, height: 16.0–17.0 mm L × 12.5 mm H. Top shape: Subcircular in ambital outline. Top domed: Greatly elevated; apical system sits raised on the corona.
SIDE: Side shape: Sides slightly inflated; slope from apex to the ambitus.
BOTTOM: Bottom shape: Adactinal surface flat (Ikins, 1940); concave to peristome (Book Author).
AMB: Amb shape: Straight and narrow; lanceolate. Widest at the peristome. Amb arrangement: Surface ornamented with two rows of alternating tubercles (19 per Ikins; 24 per Book Author).
PORE PAIRS: Arrangement: Uniserial; becoming more numerous and irregular/crowded upon approaching the peristome. Elements: Bigeminate.
TUBERCLES: Primary Perforated: No (Imperforate). Primary Crenulate: Yes. Ambulacral Tubercles: Alternating, imperforate, mammillated, and circular. Rows of fine granulation between tubercles at perradial sutures. Interambulacral Tubercles: Two rows of large alternating plates (staggered); six plates per row. Tubercles are largest at the ambitus and above.
GRANULES: Distribution: In interambulacra: two granules in the upper adradial corner, one in the lower adradial corner, and four on the medial margin of plates (Ikins, 1940). Book Author notes bands of granules along the interradial suture running to the apical cap.
FASCIOLE: Absent.
APICAL SYSTEM: Size: Large; diameter about 61% of test. Shape: Circular to subpentagonal. Plating: Oculars are "bird-shaped with legs" (Book Author) or triangular (Ikins, 1940). Suranal plate is smaller than periproct. Genital plates have a central gonopore. Ornamentation: Highly characteristic; radiating furrows extend from the suranal plate. Genital plates feature 9 very pronounced long finger-shaped suture pits.
PERIPROCT (ANUS): Shape: Triangular or deltoid (Ikins, 1940); subpentagonal (Book Author). Location: More central to the apical system; elevated.
PERISTOME (MOUTH): Size: Large; about one-half the diameter of the test. Shape: Circular. Lip: Ten greatly developed branchial incisions.
SPINES: Unknown.
SPECIMENS STUDIED & CONDITION:
- NPL 94361: Fort Worth Fm, Tarrant Co. (Sharla Rainer).
- NPL 94362: Weno Fm, Tarrant Co. (Scott Taylor).
ETYMOLOGY
Named in honor of Gayle Scott (1894–1948), Professor of Geology at Texas Christian University and authority on Texas Cretaceous paleontology.
REMARKS & COMPARISONS
Remarks: The apical system's radiating finger-shaped suture pits resemble Salenia elliotti, but S. scotti has fewer pits on each genital plate.
Comparisons:
- Salenia mexicana: S. scotti has a similar number of ambulacral tubercles (~19) but is much more elevated, has a more prominent periproct, and entirely different apical ornamentation (Ikins, 1940).
- Leptosalenia volana: S. scotti has more ambulacral tubercles (19–24 vs 15–17 in volana) and is much more elevated. The oculars in S. scotti are thinner (Book Author).
- Salenia supera: The periproct in S. scotti is more central and larger than in S. supera.
