Salenia comalensis Thompson, 2020
Plate: SaCo-10
Series: Lower Cretaceous Group: Trinity Formation: Glen Rose
Locale: Canyon Lake County: Comal Stage: Albian
Length: 8.1 mm Height: 4.0 mm
Collector: William R. Thompson, Jr.
NPL 94358 Holotype
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: NPL 94358 .
Locality: Canyon Lake, Comal County, Texas.
Stratigraphy: 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 comalensis Thompson, 2020
TYPE SPECIES: Cidaris scutigera Gray, 1835
DIAGNOSIS
A small saleniid characterized by a flat apical system similar to Leptosalenia smithi, but distinguished by its smaller size and distinct plating around the peristome.
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Trinity
Formations: Glen Rose Formation.
Stratigraphic Units: Lower Cretaceous, Unit 2., Albian.
Counties: Comal.
Abundance: Rare; only one specimen found.
Associated Fauna: Found in whitish-yellowish soft clay associated with Hyposalenia phillipsae, Pseudodiadema aguilerai, Pygopyrina hancockensis, Parorthopsis comalensis, Coenholectypus sp., and Echinothuria mccallae.
DESCRIPTION
TOP: Length, width, height: 8.1 mm L × 4.0 mm H. Top shape: Circular. Top domed: Apical disc is flat.
SIDE: Ambitus: Positioned at midpoint. Side shape: Box-like with slightly sloping sides. Profile: Height is 49% of length.
BOTTOM: Bottom shape: Flat.
AMB: Amb shape: Slightly flexing. Amb arrangement: Ambulacra are 1/3 the size of the interambulacra.
PORE PAIRS: Arrangement: Uniserial.
TUBERCLES: Primary Perforated: No (Imperforate). Primary Crenulate: Yes. Ambulacral Tubercles: Two rows of primary tubercles staggered between sets of pore pairs. Interambulacral Tubercles: Large; mamelons protruding. Areolas: Large, touching the adradial suture. Scrobicular Tubercles: Surround primary tubercles except on the adradial side.
GRANULES: Distribution: Fine granulation between ambulacral tubercles.
FASCIOLE: Absent.
APICAL SYSTEM: Size: Large; diameter 65% of test width. Shape: Round; gently raised on the corona but flat on top. Plating: Middle of oculars protrude outwards toward the ambulacra; both outer edges also protrude. Each genital plate has a gonopore. Ornamentation: Genital plates smooth; sutural pits present at each plate boundary and at midpoints between, totaling 9 for each plate.
PERIPROCT (ANUS): Shape: Hexagonal; wider than tall. Features: Surrounded by a weak lip.
PERISTOME (MOUTH): Size: Large; diameter 50% of bottom surface. Lip: Buccal notches shallow and invaginated. Plating: Ambulacral and interambulacral plating both have 3 protruding bumps; interambulacral plating protrudes more.
SPINES: Unknown.
SPECIMENS STUDIED & CONDITION: One perfect specimen studied: Holotype NPL 94358.
ETYMOLOGY
Named after Comal County, Texas, where the holotype was found.
REMARKS & COMPARISONS
Remarks: The author notes that the apical cap in Leptosalenia texana is very cone-shaped, whereas it is flat in this species. The periproct is hexagonal in S. comalensis (vs. triangular in L. texana).
Comparisons:
Plate: SaCo-10
Series: Lower Cretaceous Group: Trinity Formation: Glen Rose
Locale: Canyon Lake County: Comal Stage: Albian
Length: 8.1 mm Height: 4.0 mm
Collector: William R. Thompson, Jr.
NPL 94358 Holotype
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: NPL 94358 .
Locality: Canyon Lake, Comal County, Texas.
Stratigraphy: 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 comalensis Thompson, 2020
TYPE SPECIES: Cidaris scutigera Gray, 1835
DIAGNOSIS
A small saleniid characterized by a flat apical system similar to Leptosalenia smithi, but distinguished by its smaller size and distinct plating around the peristome.
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Trinity
Formations: Glen Rose Formation.
Stratigraphic Units: Lower Cretaceous, Unit 2., Albian.
Counties: Comal.
Abundance: Rare; only one specimen found.
Associated Fauna: Found in whitish-yellowish soft clay associated with Hyposalenia phillipsae, Pseudodiadema aguilerai, Pygopyrina hancockensis, Parorthopsis comalensis, Coenholectypus sp., and Echinothuria mccallae.
DESCRIPTION
TOP: Length, width, height: 8.1 mm L × 4.0 mm H. Top shape: Circular. Top domed: Apical disc is flat.
SIDE: Ambitus: Positioned at midpoint. Side shape: Box-like with slightly sloping sides. Profile: Height is 49% of length.
BOTTOM: Bottom shape: Flat.
AMB: Amb shape: Slightly flexing. Amb arrangement: Ambulacra are 1/3 the size of the interambulacra.
PORE PAIRS: Arrangement: Uniserial.
TUBERCLES: Primary Perforated: No (Imperforate). Primary Crenulate: Yes. Ambulacral Tubercles: Two rows of primary tubercles staggered between sets of pore pairs. Interambulacral Tubercles: Large; mamelons protruding. Areolas: Large, touching the adradial suture. Scrobicular Tubercles: Surround primary tubercles except on the adradial side.
GRANULES: Distribution: Fine granulation between ambulacral tubercles.
FASCIOLE: Absent.
APICAL SYSTEM: Size: Large; diameter 65% of test width. Shape: Round; gently raised on the corona but flat on top. Plating: Middle of oculars protrude outwards toward the ambulacra; both outer edges also protrude. Each genital plate has a gonopore. Ornamentation: Genital plates smooth; sutural pits present at each plate boundary and at midpoints between, totaling 9 for each plate.
PERIPROCT (ANUS): Shape: Hexagonal; wider than tall. Features: Surrounded by a weak lip.
PERISTOME (MOUTH): Size: Large; diameter 50% of bottom surface. Lip: Buccal notches shallow and invaginated. Plating: Ambulacral and interambulacral plating both have 3 protruding bumps; interambulacral plating protrudes more.
SPINES: Unknown.
SPECIMENS STUDIED & CONDITION: One perfect specimen studied: Holotype NPL 94358.
ETYMOLOGY
Named after Comal County, Texas, where the holotype was found.
REMARKS & COMPARISONS
Remarks: The author notes that the apical cap in Leptosalenia texana is very cone-shaped, whereas it is flat in this species. The periproct is hexagonal in S. comalensis (vs. triangular in L. texana).
Comparisons:
- Leptosalenia smithi: S. comalensis shares the flat apical cap but differs by having smaller lips, a larger peristome, different peristome plating, smaller secondary tubercles in the interambulacra, a less inflated test, less granulation below the apical cap, smaller bosses, and a larger apical cap. Sutural pit counts also differ (9 in S. comalensis vs 7–8 in L. smithi).
- Leptosalenia nolanvillensis: S. comalensis is much less inflated, has a differently shaped periproct, oculars that protrude in the center, and less apical pitting.
