Echinocyphus bordenensis Thompson, 2020
Plate: EcBo-10
Series: Lower Cretaceous Group: Fredericksburg Formation: Edwards
Locale: Fluvanna County: Borden Stage: Albian
Length: 10.9 mm Height: 4.2 mm
Collection: Dr. Steven Crane
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: NPL 94320 — Non-vertebrate Paleontology Laboratory, University of Texas
Paratypes: NPL 94321
Locality: Fluvanna, Borden County, Texas
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Acroechinoidea Smith, 1981
Superorder: Carinacea Kroh & Smith, 2010
Order: Camarodonta Jackson, 1912
Family: Zeuglopleuridae Lewis, 1986
Genus: ECHINOCYPHUS Cotteau, 1860
Species: Echinocyphus bordenensis Thompson, 2020
TYPE SPECIES: Glyphocyphus tenuistriatus Desor, 1856
DIAGNOSIS
A round, flat Echinocyphus with strongly radiated areolae restricted to center of the largest interambulacral plates .
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Fredericksburg
Formations: Edwards Formation
Stratigraphic Units: Lower Cretaceous, Albian
Counties: Borden (Fluvanna), Travis (Austin)
DESCRIPTION
TOP: Width, height: 10.9 mm W × 4.2 mm H
Top shape: Round from above
Flatness: Flat top
SIDE: Ambitus: At midpoint
Side shape: Flat top and bottom; rounded sides
BOTTOM: Bottom flat: Flat
SIZE: Range: Length 7.7 mm to 11.9 mm
AMB: Amb shape: Lanceolate; widest at ambitus, narrow at both poles
Amb width: 57% width of interambulacra
Amb primary tubercles: 2 rows of primary tubercles, alternating large then small; reduce in size towards poles
Amb arrangement: Plate compounding style Glyphocyphid: all 3 elements reach perradial suture, primary tubercle on 2 bottom elements
Amb granules: Granulation fills the plates
INTERAMB: Interamb plating: 2 rows of staggered plates; much wider than tall
Interamb primary tubercles: 7 primary tubercles per row; much larger than ambulacral tubercles
Interamb granules: Secondary tubercles throughout the plates
PORE PAIRS: Arrangement: Trigeminate, uniserial; straight except near peristome
TUBERCLES: Primary Perforated: Imperforate
Primary Crenulate: Yes, slightly.
Ornamentation: Holotype specimen displays strongly radiated areolae divided by deep sutural impressions
APICAL SYSTEM: Size: Large; 1/3 size of test
Type: Most probably hemicyclic
Missing
PERIPROCT (ANUS): Missing
PERISTOME (MOUTH): Size: 4.1 mm; 37% of width of test
Shape: Round
Lip: Notches small
Sunken: Depressed
SPECIMENS STUDIED & CONDITION
Specimen condition: 13 specimens studied. Holotype NPL 94320. Many specimens are worn, but Holotype displays surface sculpture .
ETYMOLOGY: Named for Borden County, Texas from which it is found .
REMARKS & COMPARISONS
Remarks: Species differs from known European species.
Comparisons:
Plate: EcBo-10
Series: Lower Cretaceous Group: Fredericksburg Formation: Edwards
Locale: Fluvanna County: Borden Stage: Albian
Length: 10.9 mm Height: 4.2 mm
Collection: Dr. Steven Crane
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: NPL 94320 — Non-vertebrate Paleontology Laboratory, University of Texas
Paratypes: NPL 94321
Locality: Fluvanna, Borden County, Texas
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Acroechinoidea Smith, 1981
Superorder: Carinacea Kroh & Smith, 2010
Order: Camarodonta Jackson, 1912
Family: Zeuglopleuridae Lewis, 1986
Genus: ECHINOCYPHUS Cotteau, 1860
Species: Echinocyphus bordenensis Thompson, 2020
TYPE SPECIES: Glyphocyphus tenuistriatus Desor, 1856
DIAGNOSIS
A round, flat Echinocyphus with strongly radiated areolae restricted to center of the largest interambulacral plates .
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Fredericksburg
Formations: Edwards Formation
Stratigraphic Units: Lower Cretaceous, Albian
Counties: Borden (Fluvanna), Travis (Austin)
DESCRIPTION
TOP: Width, height: 10.9 mm W × 4.2 mm H
Top shape: Round from above
Flatness: Flat top
SIDE: Ambitus: At midpoint
Side shape: Flat top and bottom; rounded sides
BOTTOM: Bottom flat: Flat
SIZE: Range: Length 7.7 mm to 11.9 mm
AMB: Amb shape: Lanceolate; widest at ambitus, narrow at both poles
Amb width: 57% width of interambulacra
Amb primary tubercles: 2 rows of primary tubercles, alternating large then small; reduce in size towards poles
Amb arrangement: Plate compounding style Glyphocyphid: all 3 elements reach perradial suture, primary tubercle on 2 bottom elements
Amb granules: Granulation fills the plates
INTERAMB: Interamb plating: 2 rows of staggered plates; much wider than tall
Interamb primary tubercles: 7 primary tubercles per row; much larger than ambulacral tubercles
Interamb granules: Secondary tubercles throughout the plates
PORE PAIRS: Arrangement: Trigeminate, uniserial; straight except near peristome
TUBERCLES: Primary Perforated: Imperforate
Primary Crenulate: Yes, slightly.
Ornamentation: Holotype specimen displays strongly radiated areolae divided by deep sutural impressions
APICAL SYSTEM: Size: Large; 1/3 size of test
Type: Most probably hemicyclic
Missing
PERIPROCT (ANUS): Missing
PERISTOME (MOUTH): Size: 4.1 mm; 37% of width of test
Shape: Round
Lip: Notches small
Sunken: Depressed
SPECIMENS STUDIED & CONDITION
Specimen condition: 13 specimens studied. Holotype NPL 94320. Many specimens are worn, but Holotype displays surface sculpture .
ETYMOLOGY: Named for Borden County, Texas from which it is found .
REMARKS & COMPARISONS
Remarks: Species differs from known European species.
Comparisons:
- E. tenuistriatus: E. bordenensis has a round test with larger tubercles (not pentagonal like tenuistriatus).
- E. mespilia: E. bordenensis test is not as inflated and buccal notches are not as large.
- E. difficilis: In E. bordenensis, the strongly radiated areolae of interambulacral tubercles are restricted to the center of plates, unlike the plating of E. difficilis .
