Coenholectypus latus Thompson, 2016
Plate: CoLa-10
Series: Upper Cretaceous Group: Eagle Ford Formation: Boquillas
Locale: Comstock County: Val Verde Stage: Turonian
Length: 4.0 mm Height: 2.4 mm Specimen in photo: NPL 82995 (Holotype)
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: NPL 82995 — Non-vertebrate Paleontology Laboratory, University of Texas
Locality: Comstock, Val Verde County, Texas
Systematic Paleontology
CLASS: ECHINOIDEA Leske, 1778
SUBCLASS: EUECHINOIDEA Bronn, 1860
INFRACLASS: IRREGULARIA Latreille, 1825
SUPERORDER: GNATHOSTOMATA Zittel, 1879
ORDER: HOLECTYPOIDA Duncan, 1889
FAMILY: COENHOLECTYPIDAE Smith & Wright, 1999
GENUS: COENHOLECTYPUS Pomel, 1883
SPECIES: Coenholectypus latus Thompson, 2016
TYPE SPECIES: Discoidea depressa L. Agassiz, 1839
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Eagle Ford
Formations: Boquillas Formation
Stratigraphic Units: Upper Cretaceous, Turonian
Counties: Val Verde County
DESCRIPTION
TOP: Length, width, height: 4.0 mm L × 2.4 mm H
Top shape: Round from above
Top domed: Inflated, evenly domed
SIDE: Ambitus: Rounded; located 35% from adoral side
Side shape: Inflated
BOTTOM: Bottom flat: Flat
Bottom shape: Concave
AMB: Amb shape: Lanceolate, very pointed; straight to ambitus
Amb width: Widest at ambitus; adorally begins to narrow
INTERAMB: Interamb width: Slightly less than two times size of ambulacra at ambitus
PORE PAIRS: Shape: Small
Arrangement: Uniserial, oblique
TUBERCLES: Primary tubercles:
APICAL SYSTEM: Size / Location: Central, small
Plates: Genitals pentagonal; 5 gonopores
Madreporite: Central
PERIPROCT (ANUS): Shape & Size: Tear-drop shaped, pointed at both ends, longer than wide
Location: Marginal (at the ambitus); occupies the margin, half above ambitus and half below.
Visibility: Cannot clearly be seen from above; clearly visible from side; barely visible from below
PERISTOME (MOUTH): Size: 55% of diameter of test
Shape: Round
Lip: Notches small
SPECIMENS STUDIED & CONDITION
Three specimens studied (Holotype and Paratype). Identified as likely juveniles/micro-echinoids.
ETYMOLOGY: Named "latus", the Latin word for "side", because of the placement of the periproct.
REMARKS & COMPARISONS
Remarks: Coenholectypus latus is a tiny species, likely described from juvenile material ("micro"). It is characterized by the specific placement of the large, double-pointed periproct at the ambitus. The name "latus" (Latin for "side") refers to this marginal placement.
Comparisons: Distinguished from other Coenholectypus species by the periproct placement (marginal vs. infra-marginal) and shape. It is smaller than Coenholectypus nanus.
Plate: CoLa-10
Series: Upper Cretaceous Group: Eagle Ford Formation: Boquillas
Locale: Comstock County: Val Verde Stage: Turonian
Length: 4.0 mm Height: 2.4 mm Specimen in photo: NPL 82995 (Holotype)
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: NPL 82995 — Non-vertebrate Paleontology Laboratory, University of Texas
Locality: Comstock, Val Verde County, Texas
Systematic Paleontology
CLASS: ECHINOIDEA Leske, 1778
SUBCLASS: EUECHINOIDEA Bronn, 1860
INFRACLASS: IRREGULARIA Latreille, 1825
SUPERORDER: GNATHOSTOMATA Zittel, 1879
ORDER: HOLECTYPOIDA Duncan, 1889
FAMILY: COENHOLECTYPIDAE Smith & Wright, 1999
GENUS: COENHOLECTYPUS Pomel, 1883
SPECIES: Coenholectypus latus Thompson, 2016
TYPE SPECIES: Discoidea depressa L. Agassiz, 1839
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Eagle Ford
Formations: Boquillas Formation
Stratigraphic Units: Upper Cretaceous, Turonian
Counties: Val Verde County
DESCRIPTION
TOP: Length, width, height: 4.0 mm L × 2.4 mm H
Top shape: Round from above
Top domed: Inflated, evenly domed
SIDE: Ambitus: Rounded; located 35% from adoral side
Side shape: Inflated
BOTTOM: Bottom flat: Flat
Bottom shape: Concave
AMB: Amb shape: Lanceolate, very pointed; straight to ambitus
Amb width: Widest at ambitus; adorally begins to narrow
INTERAMB: Interamb width: Slightly less than two times size of ambulacra at ambitus
PORE PAIRS: Shape: Small
Arrangement: Uniserial, oblique
TUBERCLES: Primary tubercles:
- Ambulacra: 2 rows of small, irregular tubercles
- Interambulacra: Primary tubercles appear irregular
Density variation: More tubercles on adoral surface
APICAL SYSTEM: Size / Location: Central, small
Plates: Genitals pentagonal; 5 gonopores
Madreporite: Central
PERIPROCT (ANUS): Shape & Size: Tear-drop shaped, pointed at both ends, longer than wide
Location: Marginal (at the ambitus); occupies the margin, half above ambitus and half below.
Visibility: Cannot clearly be seen from above; clearly visible from side; barely visible from below
PERISTOME (MOUTH): Size: 55% of diameter of test
Shape: Round
Lip: Notches small
SPECIMENS STUDIED & CONDITION
Three specimens studied (Holotype and Paratype). Identified as likely juveniles/micro-echinoids.
ETYMOLOGY: Named "latus", the Latin word for "side", because of the placement of the periproct.
REMARKS & COMPARISONS
Remarks: Coenholectypus latus is a tiny species, likely described from juvenile material ("micro"). It is characterized by the specific placement of the large, double-pointed periproct at the ambitus. The name "latus" (Latin for "side") refers to this marginal placement.
Comparisons: Distinguished from other Coenholectypus species by the periproct placement (marginal vs. infra-marginal) and shape. It is smaller than Coenholectypus nanus.
