Leptosalenia smithi Thompson, 2016
Plate: LeSm-10
Series: Lower Cretaceous Group: Trinity Formation: Glen Rose
Locale: Canyon Lake County: Comal Stage: Albian
Length: 19.3 mm Height: 11.1 mm
Specimen in photo: NPL 70933 Holotype
Collector: William R. Thompson, Jr.
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: NPL 70933.
Locality: Mystic Shores Subdivision, Canyon Lake, Comal County, Texas.
Stratigraphy: Glen Rose Formation, Trinity 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: LEPTOSALENIA Smith & Wright, 1990
Species: Leptosalenia smithi Thompson, 2016
TYPE SPECIES: Salenia prestensis Desor, 1856
DIAGNOSIS
A Leptosalenia morphologically similar to L. texana but distinguished by a flat apical system (not conical) and the presence of perforations (gonopores) on all five genital plates.
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Trinity
Formations: Glen Rose Formation.
Stratigraphic Units: Lower Cretaceous, Albian.
Counties: Comal.
Abundance: Rare; only two specimens found.
Associated Fauna: Found in a mixed assemblage including Upper Member (Unit 3) fauna (Goniopygus whitneyi, Loriolia rosana, Polydiadema travisensis, Tetragramma tenerum, Coenholectypus planatus, Plagiochasma texanum, Heteraster obliquatus) and Lower Member (Unit 2) fauna (Pygopyrina hancockensis). Matrix is a soft, whitish-yellow clay.
DESCRIPTION
TOP: Length, width, height: 19.3 mm L × 11.1 mm H.
Top shape: Circular outline.
Top domed: Apical disc is flat.
SIDE: Ambitus: Positioned at midpoint.
Side shape: Sides gently sloping.
BOTTOM: Bottom shape: Flat.
AMB: Amb shape: Straight with a slight flexure near the apical disc.
Amb width: Interambulacra are 3.5 times the size of the ambulacra.
PORE PAIRS: Arrangement: Uniserial.
TUBERCLES: Primary Perforated: No (Imperforate).
Primary Crenulate: Yes.
Ambulacral Tubercles: Two rows staggered between sets of pore pairs.
Interambulacral Tubercles: Large; mamelons spherical.
Areolas: Large.
Scrobicular Tubercles: Surround primary tubercles except on the adradial side.
GRANULES: Distribution: Further granulation present just below the apical system and at the interradial and adradial sutures.
FASCIOLE: Absent.
APICAL SYSTEM: Shape: Round; gently raised on the corona but flat on top. Slight indentation on each side of the
oculars.
Plating: Each genital plate has a gonopore. Genital plates are smooth.
Ornamentation: Sutural pits present at each plate boundary and at midpoints between, totaling 7 for each plate.
PERIPROCT (ANUS): Shape: Oval; bulges toward the center.
Features: Surrounded by a weak lip.
PERISTOME (MOUTH): Size: Large; diameter 50% of bottom surface.
Lip: Buccal notches very deep.
SPINES: Unknown.
SPECIMENS STUDIED & CONDITION: One perfect specimen studied: Holotype NPL 70933.
ETYMOLOGY
Named after Dr. Andrew Smith (Natural History Museum, London) in recognition of his significant contributions to echinoid paleontology.
REMARKS & COMPARISONS
Remarks: This species is likely the same as the echinoid described as Leptosalenia sp. cf. L. texana by Smith & Rader (2009) from the Glen Rose Formation.
Comparisons:
Plate: LeSm-10
Series: Lower Cretaceous Group: Trinity Formation: Glen Rose
Locale: Canyon Lake County: Comal Stage: Albian
Length: 19.3 mm Height: 11.1 mm
Specimen in photo: NPL 70933 Holotype
Collector: William R. Thompson, Jr.
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: NPL 70933.
Locality: Mystic Shores Subdivision, Canyon Lake, Comal County, Texas.
Stratigraphy: Glen Rose Formation, Trinity Group.
SYNONYMY
- Leptosalenia sp. cf. L. texana (Smith & Rader, 2009)
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 smithi Thompson, 2016
TYPE SPECIES: Salenia prestensis Desor, 1856
DIAGNOSIS
A Leptosalenia morphologically similar to L. texana but distinguished by a flat apical system (not conical) and the presence of perforations (gonopores) on all five genital plates.
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Trinity
Formations: Glen Rose Formation.
Stratigraphic Units: Lower Cretaceous, Albian.
Counties: Comal.
Abundance: Rare; only two specimens found.
Associated Fauna: Found in a mixed assemblage including Upper Member (Unit 3) fauna (Goniopygus whitneyi, Loriolia rosana, Polydiadema travisensis, Tetragramma tenerum, Coenholectypus planatus, Plagiochasma texanum, Heteraster obliquatus) and Lower Member (Unit 2) fauna (Pygopyrina hancockensis). Matrix is a soft, whitish-yellow clay.
DESCRIPTION
TOP: Length, width, height: 19.3 mm L × 11.1 mm H.
Top shape: Circular outline.
Top domed: Apical disc is flat.
SIDE: Ambitus: Positioned at midpoint.
Side shape: Sides gently sloping.
BOTTOM: Bottom shape: Flat.
AMB: Amb shape: Straight with a slight flexure near the apical disc.
Amb width: Interambulacra are 3.5 times the size of the ambulacra.
PORE PAIRS: Arrangement: Uniserial.
TUBERCLES: Primary Perforated: No (Imperforate).
Primary Crenulate: Yes.
Ambulacral Tubercles: Two rows staggered between sets of pore pairs.
Interambulacral Tubercles: Large; mamelons spherical.
Areolas: Large.
Scrobicular Tubercles: Surround primary tubercles except on the adradial side.
GRANULES: Distribution: Further granulation present just below the apical system and at the interradial and adradial sutures.
FASCIOLE: Absent.
APICAL SYSTEM: Shape: Round; gently raised on the corona but flat on top. Slight indentation on each side of the
oculars.
Plating: Each genital plate has a gonopore. Genital plates are smooth.
Ornamentation: Sutural pits present at each plate boundary and at midpoints between, totaling 7 for each plate.
PERIPROCT (ANUS): Shape: Oval; bulges toward the center.
Features: Surrounded by a weak lip.
PERISTOME (MOUTH): Size: Large; diameter 50% of bottom surface.
Lip: Buccal notches very deep.
SPINES: Unknown.
SPECIMENS STUDIED & CONDITION: One perfect specimen studied: Holotype NPL 70933.
ETYMOLOGY
Named after Dr. Andrew Smith (Natural History Museum, London) in recognition of his significant contributions to echinoid paleontology.
REMARKS & COMPARISONS
Remarks: This species is likely the same as the echinoid described as Leptosalenia sp. cf. L. texana by Smith & Rader (2009) from the Glen Rose Formation.
Comparisons:
- L. texana: L. smithi differs by having a flat apical cap (vs. very cone-shaped in texana), an oval periproct (vs. triangular), and a less inflated test. Additionally, the sutural pit counts differ: L. texana typically has 9 pits surrounding genital plates II and III, whereas L. smithi has 8 pits on genital II and 7 pits on genital III.
