Heterosalenia ridiculum Thompson 2016
Plate: HeRi-10
Series: Lower Cretaceous Group: Fredericksburg Formation: Edwards
Locale: Chalk Mountain County: Somervell Stage: Albian
Length: 17.7 mm Height: 10.3 mm
Collector: Dr. Stephen Crane
Holotype NPL 82984 Non-vertebrate Paleo. Lab., Univ. of Texas
Plate: HeRi-20
Series: Lower Cretaceous Group: Fredericksburg Formation: Edwards
Locale: South of Lampasas County: Burnet Stage: Albian
Length: 17.7 mm Height: 10.3 mm
Collector: Marc Vries sold to P. Nicolleau
HOLOTYPE INFO:
Holotype: NPL 82984 .
Locality: Chalk Mountain, Somervell County, Texas.
Stratigraphy: Edwards 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: HETEROSALENIA Cotteau, 1861
Species: Heterosalenia ridiculum
TYPE SPECIES: Heterosalenia martini Cotteau, 1861
DIAGNOSIS
A Heterosalenia from the Lower Cretaceous with a hemicyclic apical system and ambulacra that are only slightly wavy.
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Fredericksburg
Formations: Edwards Formation
Stratigraphic Units: Lower Cretaceous, Albian
Counties: Somervell, Burnet (Texas)
Abundance: Rare; only two specimens known.
DESCRIPTION
TOP: Shape: Round, slightly pentagonal.
Apical System: Central, slightly raised.
SIDE: Ambitus: Positioned at 40% of height from adoral surface.
Side shape: Depressed; wide flat base.
BOTTOM: Bottom shape: Depressed.
AMB: Amb shape: Pointed at apical system, widest adorally; slightly wavy.
Amb width: Interambulacra are more than four times the width of ambulacra at the ambitus.
Amb arrangement: Two rows of 29–30 tubercles in ambulacra. Small granules present between rows of ambulacral tubercles.
PORE PAIRS: Arrangement: Uniserial.
Elements: Unigeminate (simple) over most of the test; becoming trigeminate adorally.
Shape: Round.
TUBERCLES: Primary Perforated: Interambulacral tubercles perforated.
Primary Crenulate: Interambulacral tubercles crenulated.
Ambulacral Tubercles: Non-crenulate and imperforate. One primary tubercle on each ambulacral plate, located at the margin adjacent to pore pairs.
Interambulacral Tubercles: Two rows of 4 primary tubercles (one on each interambulacral plate). Mamelons large and pronounced.
Distribution: Primary tubercles are surrounded by secondary tubercles. Naked vertically between plates; not naked at adradial or interradial suture.
Granulation: Granules concentrated very densely below the apical system down to the uppermost primary tubercles. Granulation reduces at the peristome.
APICAL SYSTEM: Size: Measures 43% of the width of the test.
Shape: Pentagonal; hemicyclic.
Plating: Oculars are large, curved inward, with several bumps on the outer edge. Genital plates vary in odd shapes (worn in holotype); gonopores located near the outer edges of each genital plate with a suture approaching them.
Ornamentation: Suture pits large with some tubercles; deep lines between every plate.
PERIPROCT (ANUS): Shape: Suboval.
Location: Aligned with ambulacrum; equal in size to suranal plate.
Ornamentation: Ring of small tubercles surrounds the periproct.
PERISTOME (MOUTH): Size: Measuring 51% of the diameter.
Sunken: Slightly depressed.
Lip: Notches small, evenly spaced, with thickened lips.
SPINES: Unknown.
SPECIMENS STUDIED & CONDITION: Holotype NPL 82984. A second specimen (Plate HeRi-20) from Burnet County collected by Marc de Vries (sold to P. Nicolleau) was also referenced.
ETYMOLOGY
The name "ridiculum" is Latin for "weird" or "joke," referring to the odd-shaped genital plates.
REMARKS & COMPARISONS
Remarks: This species was originally described as Pseudocidaris ridiculum . A better-preserved specimen found in the Edwards Formation near Lampasas, Texas, by Marc de Vries (collection of Philippe Nicolleau) clarified the apical system structure, leading to its reassignment to Heterosalenia. This represents the first Heterosalenia reported from Texas.
Plate: HeRi-10
Series: Lower Cretaceous Group: Fredericksburg Formation: Edwards
Locale: Chalk Mountain County: Somervell Stage: Albian
Length: 17.7 mm Height: 10.3 mm
Collector: Dr. Stephen Crane
Holotype NPL 82984 Non-vertebrate Paleo. Lab., Univ. of Texas
Plate: HeRi-20
Series: Lower Cretaceous Group: Fredericksburg Formation: Edwards
Locale: South of Lampasas County: Burnet Stage: Albian
Length: 17.7 mm Height: 10.3 mm
Collector: Marc Vries sold to P. Nicolleau
HOLOTYPE INFO:
Holotype: NPL 82984 .
Locality: Chalk Mountain, Somervell County, Texas.
Stratigraphy: Edwards Formation, Fredericksburg Group.
SYNONYMY
- Pseudocidaris ridiculum Thompson, 2016 (p. 74-75, Fig. 60a-d)
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: HETEROSALENIA Cotteau, 1861
Species: Heterosalenia ridiculum
TYPE SPECIES: Heterosalenia martini Cotteau, 1861
DIAGNOSIS
A Heterosalenia from the Lower Cretaceous with a hemicyclic apical system and ambulacra that are only slightly wavy.
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Fredericksburg
Formations: Edwards Formation
Stratigraphic Units: Lower Cretaceous, Albian
Counties: Somervell, Burnet (Texas)
Abundance: Rare; only two specimens known.
DESCRIPTION
TOP: Shape: Round, slightly pentagonal.
Apical System: Central, slightly raised.
SIDE: Ambitus: Positioned at 40% of height from adoral surface.
Side shape: Depressed; wide flat base.
BOTTOM: Bottom shape: Depressed.
AMB: Amb shape: Pointed at apical system, widest adorally; slightly wavy.
Amb width: Interambulacra are more than four times the width of ambulacra at the ambitus.
Amb arrangement: Two rows of 29–30 tubercles in ambulacra. Small granules present between rows of ambulacral tubercles.
PORE PAIRS: Arrangement: Uniserial.
Elements: Unigeminate (simple) over most of the test; becoming trigeminate adorally.
Shape: Round.
TUBERCLES: Primary Perforated: Interambulacral tubercles perforated.
Primary Crenulate: Interambulacral tubercles crenulated.
Ambulacral Tubercles: Non-crenulate and imperforate. One primary tubercle on each ambulacral plate, located at the margin adjacent to pore pairs.
Interambulacral Tubercles: Two rows of 4 primary tubercles (one on each interambulacral plate). Mamelons large and pronounced.
Distribution: Primary tubercles are surrounded by secondary tubercles. Naked vertically between plates; not naked at adradial or interradial suture.
Granulation: Granules concentrated very densely below the apical system down to the uppermost primary tubercles. Granulation reduces at the peristome.
APICAL SYSTEM: Size: Measures 43% of the width of the test.
Shape: Pentagonal; hemicyclic.
Plating: Oculars are large, curved inward, with several bumps on the outer edge. Genital plates vary in odd shapes (worn in holotype); gonopores located near the outer edges of each genital plate with a suture approaching them.
Ornamentation: Suture pits large with some tubercles; deep lines between every plate.
PERIPROCT (ANUS): Shape: Suboval.
Location: Aligned with ambulacrum; equal in size to suranal plate.
Ornamentation: Ring of small tubercles surrounds the periproct.
PERISTOME (MOUTH): Size: Measuring 51% of the diameter.
Sunken: Slightly depressed.
Lip: Notches small, evenly spaced, with thickened lips.
SPINES: Unknown.
SPECIMENS STUDIED & CONDITION: Holotype NPL 82984. A second specimen (Plate HeRi-20) from Burnet County collected by Marc de Vries (sold to P. Nicolleau) was also referenced.
ETYMOLOGY
The name "ridiculum" is Latin for "weird" or "joke," referring to the odd-shaped genital plates.
REMARKS & COMPARISONS
Remarks: This species was originally described as Pseudocidaris ridiculum . A better-preserved specimen found in the Edwards Formation near Lampasas, Texas, by Marc de Vries (collection of Philippe Nicolleau) clarified the apical system structure, leading to its reassignment to Heterosalenia. This represents the first Heterosalenia reported from Texas.
