Salenia granula Thompson, 2020
Plate: SaGr-10
Series: Lower Cretaceous Group: Trinity Formation: Glen Rose
Locale: Canyon County: Comal Stage: Albian
Length: 20.5 mm Height: 11.6 mm
Collector: William Thompson
Holotype: NPL 94359
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: NPL 94359 .
Locality: Hancock (Canyon Lake area), Comal County, Texas.
Stratigraphy: "Salenia texana zone", Glen Rose Formation, Trinity Group.
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 granula Thompson, 2020
TYPE SPECIES: Cidaris scutigera Gray, 1835
DIAGNOSIS
A depressed, medium-sized Salenia distinguished by straight ambulacra and large, protruding ocular plates. The interambulacra are characterized by a high density of large granules.
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Trinity
Formations: Glen Rose Formation.
Stratigraphic Units: Lower Cretaceous, Albian.
Counties: Comal.
Abundance: Rare; only one specimen found.
Associated Fauna: Found in grey matrix associated with Leptosalenia texana, Leptosalenia glenrosensis, Heteraster obliquatus, Pliotoxaster comanchei, Coenholectypus planatus, Coenholectypus ovatus, and Tetragramma donaldtrumpi.
DESCRIPTION
TOP: Length, width, height: 20.5 mm L × 11.6 mm H. Top shape: Circular outline. Top domed: Apical system sits on the corona, only slightly raised. Apex is located at the inside lip of the periproct.
SIDE: Ambitus: Positioned 33% of height from the adoral surface. Side shape: Depressed profile.
BOTTOM: Bottom shape: Concave to the peristome.
AMB: Amb shape: Straight, lanceolate; widest at the peristome. Amb arrangement: Two rows of 18–19 tubercles. Amb width: Interambulacra are just under 3 times the size of the ambulacra.
PORE PAIRS: Arrangement: Uniserial; becoming crowded at the peristome. Elements: Bigeminate.
TUBERCLES: Primary Perforated: No (Imperforate). Primary Crenulate: Yes. Ambulacral Tubercles: Fine granulation present between tubercles. Interambulacral Tubercles: Two rows of five tubercles; largest are at the ambitus. Scrobicular Tubercles: Surround each primary tubercle except on the adradial side, above, and below.
GRANULES: Distribution: Band of large granules (2 wide, slightly smaller than scrobicular tubercles) runs along the interradial suture. This band starts below the apical cap, disappears between the top of the 2nd row of primary tubercles, reappears thickest above/below the ambitus, and disappears above the peristome. Smaller granules are thick from slightly above to mostly below the ambitus.
FASCIOLE: Absent.
APICAL SYSTEM: Size: Medium; diameter 55% of test diameter. Shape: Subpentagonal; 15 outer "points" formed by the edges of ocular and genital plates. Plating: Each genital plate has a central gonopore. Oculars are protruding and "bird-shaped." Condition: Suranal plate and part of Genital 5 missing in holotype.
PERIPROCT (ANUS): Shape: Appears subpentagonal. Features: Surrounded by a lip. Condition: Broken in holotype.
PERISTOME (MOUTH): Size: Diameter 50% of test diameter. Lip: Ten large, invaginated buccal notches. Lips present on the interambulacral side of notches only.
SPINES: Unknown.
SPECIMENS STUDIED & CONDITION: One specimen studied: Holotype NPL 94359.
ETYMOLOGY
Named granula for the large number of granules present in the interambulacral areas.
REMARKS & COMPARISONS
Remarks: This species is most similar to Salenia supera.
Comparisons:
Plate: SaGr-10
Series: Lower Cretaceous Group: Trinity Formation: Glen Rose
Locale: Canyon County: Comal Stage: Albian
Length: 20.5 mm Height: 11.6 mm
Collector: William Thompson
Holotype: NPL 94359
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: NPL 94359 .
Locality: Hancock (Canyon Lake area), Comal County, Texas.
Stratigraphy: "Salenia texana zone", Glen Rose Formation, Trinity Group.
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 granula Thompson, 2020
TYPE SPECIES: Cidaris scutigera Gray, 1835
DIAGNOSIS
A depressed, medium-sized Salenia distinguished by straight ambulacra and large, protruding ocular plates. The interambulacra are characterized by a high density of large granules.
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Trinity
Formations: Glen Rose Formation.
Stratigraphic Units: Lower Cretaceous, Albian.
Counties: Comal.
Abundance: Rare; only one specimen found.
Associated Fauna: Found in grey matrix associated with Leptosalenia texana, Leptosalenia glenrosensis, Heteraster obliquatus, Pliotoxaster comanchei, Coenholectypus planatus, Coenholectypus ovatus, and Tetragramma donaldtrumpi.
DESCRIPTION
TOP: Length, width, height: 20.5 mm L × 11.6 mm H. Top shape: Circular outline. Top domed: Apical system sits on the corona, only slightly raised. Apex is located at the inside lip of the periproct.
SIDE: Ambitus: Positioned 33% of height from the adoral surface. Side shape: Depressed profile.
BOTTOM: Bottom shape: Concave to the peristome.
AMB: Amb shape: Straight, lanceolate; widest at the peristome. Amb arrangement: Two rows of 18–19 tubercles. Amb width: Interambulacra are just under 3 times the size of the ambulacra.
PORE PAIRS: Arrangement: Uniserial; becoming crowded at the peristome. Elements: Bigeminate.
TUBERCLES: Primary Perforated: No (Imperforate). Primary Crenulate: Yes. Ambulacral Tubercles: Fine granulation present between tubercles. Interambulacral Tubercles: Two rows of five tubercles; largest are at the ambitus. Scrobicular Tubercles: Surround each primary tubercle except on the adradial side, above, and below.
GRANULES: Distribution: Band of large granules (2 wide, slightly smaller than scrobicular tubercles) runs along the interradial suture. This band starts below the apical cap, disappears between the top of the 2nd row of primary tubercles, reappears thickest above/below the ambitus, and disappears above the peristome. Smaller granules are thick from slightly above to mostly below the ambitus.
FASCIOLE: Absent.
APICAL SYSTEM: Size: Medium; diameter 55% of test diameter. Shape: Subpentagonal; 15 outer "points" formed by the edges of ocular and genital plates. Plating: Each genital plate has a central gonopore. Oculars are protruding and "bird-shaped." Condition: Suranal plate and part of Genital 5 missing in holotype.
PERIPROCT (ANUS): Shape: Appears subpentagonal. Features: Surrounded by a lip. Condition: Broken in holotype.
PERISTOME (MOUTH): Size: Diameter 50% of test diameter. Lip: Ten large, invaginated buccal notches. Lips present on the interambulacral side of notches only.
SPINES: Unknown.
SPECIMENS STUDIED & CONDITION: One specimen studied: Holotype NPL 94359.
ETYMOLOGY
Named granula for the large number of granules present in the interambulacral areas.
REMARKS & COMPARISONS
Remarks: This species is most similar to Salenia supera.
Comparisons:
- Salenia supera: S. granula is not as inflated as S. supera. It possesses more and larger granules along the interradial suture, a much smaller and flatter apical system, much larger ocular plates, and larger peristome notches.
