Leptosalenia hancockensis Thompson, 2016
Plate: LeHa-10
Series: Lower Cretaceous Group: Trinity Formation: Glen Rose
Locale: Startzville County: Comal Stage: Albian
Length: 14.2 mm Height: 6.6 mm
Specimen in photo: NPL 73958 Holotype
Collector: William R. Thompson, Jr.
Collector: William R. Thompson, Jr.
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: NPL 73958.
Paratype: NPL 73959.
Locality: Startzville (Hancock locality), 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: LEPTOSALENIA Smith & Wright, 1990
Species: Leptosalenia hancockensis Thompson, 2016
TYPE SPECIES: Salenia prestensis Desor, 1856
DIAGNOSIS
A Leptosalenia characterized by a specific sutural pit arrangement: Ocular I with 3 pits, Ocular II with 5 pits, and Oculars III, IV, and V with 4 pits. The apical system is flat on the outer edges with a rapidly sloping periproct in the center. Interambulacra feature 2 large primary tubercles and 2 secondary tubercles per row.
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Trinity
Formations: Glen Rose Formation ("Salenia zone").
Stratigraphic Units: Lower Cretaceous, Albian.
Counties: Comal.
Abundance: Rare; found only in one location in Comal County.
Associated Fauna: Found in association with Leptosalenia texana, Heteraster obliquatus, Pliotoxaster comanchei, Coenholectypus planatus, Coenholectypus ovatus, Tetragramma hancockensis, and Phyllacanthus tysoni.
DESCRIPTION
TOP: Length, width, height: 14.2 mm L × 6.6 mm H.
Top shape: Circular outline.
Top domed: Apical system sits on the corona as a raised cap.
SIDE: Ambitus: Positioned 34% of height from the adoral surface.
Side shape: Depressed profile.
BOTTOM: Bottom shape: Flat.
AMB: Amb shape: Flexuous; widest at the peristome.
Amb arrangement: Two rows of 19 tubercles run the length of the ambulacra.
Amb width: Interambulacra are just over 4.5 times the size of the ambulacra.
PORE PAIRS: Arrangement: Uniserial; becoming crowded at the peristome.
TUBERCLES: Primary Perforated: No (Imperforate per Family).
Primary Crenulate: Yes.
Ambulacral Tubercles: 19 per row.
Interambulacral Tubercles: Two rows of four tubercles (two large, two small/very small).
Areolas: Raised; mamelons large and protruding.
Scrobicular Tubercles: Surround each primary tubercle except on the adradial side.
GRANULES: Granulation present along the interradial suture.
FASCIOLE: Absent.
APICAL SYSTEM: Size: Large; diameter ~53% of test diameter.
Shape: Rounded/circular; genital plate outer edges are rounded. Flat on outer edges, sloping quickly toward the corona/periproct.
Plating: Each genital plate has a central gonopore. Ocular outer edges are scalloped with three rounded bumps (center bump smallest).
Ornamentation: Sutural pits vary by plate: Ocular I (3 pits), Ocular II (5 pits), Oculars III–V (4 pits).
PERIPROCT (ANUS): Shape: Somewhat triangular.
Location: Central (Apex at inside lip).
Features: Surrounded by a lip; slopes quickly from the flat apical disc.
PERISTOME (MOUTH): Size: Diameter 46% of test diameter.
Lip: Ten buccal notches; lips present on the interambulacral side of notches only.
SPINES: Unknown.
SPECIMENS STUDIED & CONDITION: Two specimens studied (Holotype NPL 73958, Paratype NPL 73959).
ETYMOLOGY
Named after the Hancock locality in Comal County, Texas, where it was found.
REMARKS & COMPARISONS
Remarks: This species is distinguished by the unique configuration of the sutural pits and the profile of the apical system (flat edges with a quickly sloping periproct), which is unlike any other Leptosalenia.
Comparisons:
Plate: LeHa-10
Series: Lower Cretaceous Group: Trinity Formation: Glen Rose
Locale: Startzville County: Comal Stage: Albian
Length: 14.2 mm Height: 6.6 mm
Specimen in photo: NPL 73958 Holotype
Collector: William R. Thompson, Jr.
Collector: William R. Thompson, Jr.
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: NPL 73958.
Paratype: NPL 73959.
Locality: Startzville (Hancock locality), 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: LEPTOSALENIA Smith & Wright, 1990
Species: Leptosalenia hancockensis Thompson, 2016
TYPE SPECIES: Salenia prestensis Desor, 1856
DIAGNOSIS
A Leptosalenia characterized by a specific sutural pit arrangement: Ocular I with 3 pits, Ocular II with 5 pits, and Oculars III, IV, and V with 4 pits. The apical system is flat on the outer edges with a rapidly sloping periproct in the center. Interambulacra feature 2 large primary tubercles and 2 secondary tubercles per row.
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Trinity
Formations: Glen Rose Formation ("Salenia zone").
Stratigraphic Units: Lower Cretaceous, Albian.
Counties: Comal.
Abundance: Rare; found only in one location in Comal County.
Associated Fauna: Found in association with Leptosalenia texana, Heteraster obliquatus, Pliotoxaster comanchei, Coenholectypus planatus, Coenholectypus ovatus, Tetragramma hancockensis, and Phyllacanthus tysoni.
DESCRIPTION
TOP: Length, width, height: 14.2 mm L × 6.6 mm H.
Top shape: Circular outline.
Top domed: Apical system sits on the corona as a raised cap.
SIDE: Ambitus: Positioned 34% of height from the adoral surface.
Side shape: Depressed profile.
BOTTOM: Bottom shape: Flat.
AMB: Amb shape: Flexuous; widest at the peristome.
Amb arrangement: Two rows of 19 tubercles run the length of the ambulacra.
Amb width: Interambulacra are just over 4.5 times the size of the ambulacra.
PORE PAIRS: Arrangement: Uniserial; becoming crowded at the peristome.
TUBERCLES: Primary Perforated: No (Imperforate per Family).
Primary Crenulate: Yes.
Ambulacral Tubercles: 19 per row.
Interambulacral Tubercles: Two rows of four tubercles (two large, two small/very small).
Areolas: Raised; mamelons large and protruding.
Scrobicular Tubercles: Surround each primary tubercle except on the adradial side.
GRANULES: Granulation present along the interradial suture.
FASCIOLE: Absent.
APICAL SYSTEM: Size: Large; diameter ~53% of test diameter.
Shape: Rounded/circular; genital plate outer edges are rounded. Flat on outer edges, sloping quickly toward the corona/periproct.
Plating: Each genital plate has a central gonopore. Ocular outer edges are scalloped with three rounded bumps (center bump smallest).
Ornamentation: Sutural pits vary by plate: Ocular I (3 pits), Ocular II (5 pits), Oculars III–V (4 pits).
PERIPROCT (ANUS): Shape: Somewhat triangular.
Location: Central (Apex at inside lip).
Features: Surrounded by a lip; slopes quickly from the flat apical disc.
PERISTOME (MOUTH): Size: Diameter 46% of test diameter.
Lip: Ten buccal notches; lips present on the interambulacral side of notches only.
SPINES: Unknown.
SPECIMENS STUDIED & CONDITION: Two specimens studied (Holotype NPL 73958, Paratype NPL 73959).
ETYMOLOGY
Named after the Hancock locality in Comal County, Texas, where it was found.
REMARKS & COMPARISONS
Remarks: This species is distinguished by the unique configuration of the sutural pits and the profile of the apical system (flat edges with a quickly sloping periproct), which is unlike any other Leptosalenia.
Comparisons:
- Salenia stenzeli: The sutural pits on Oculars IV and V match S. stenzeli, but the counts differ on other plates, and the ocular shape is different.
- Salenia pseudowhitneyi: Sutural pits are also similar to this species.
