Clypeaster marinanus Jackson, 1937
Plate: ClMa-10
Series: Oligocene Group: Catahoula Formation: Anahuac
Locale: Damon Mound County: Brazoria Stage: Chattian
Length: 63.5 mm Width: 54.7 mm Height: 14.3 mm
Specimens in photos: Fragment 2058.2 (Texas), NPL 894 (Mexico)
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: USNM (Likely stored at Smithsonian National Museum of Natural History, described in Proc. U.S. Nat. Mus. 84: 227-237
Locality: Mexico (Jackson, 1937).
Systematic Paleontology
CLASS: ECHINOIDEA Leske, 1778
SUBCLASS: EUECHINOIDEA Bronn, 1860
INFRACLASS: IRREGULARIA Latreille, 1825
SUPERORDER: GNATHOSTOMATA Zittel, 1879
ORDER: CLYPEASTEROIDA A. Agassiz, 1872
FAMILY: CLYPEASTERIDAE L. Agassiz, 1835
GENUS: CLYPEASTER Lamarck, 1801
SPECIES: Clypeaster marinanus Jackson, 1937
TYPE SPECIES: Clypeaster rosaceus (Linnaeus, 1758)
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Catahoula
Formations: Anahuac Formation
Stratigraphic Units: Oligocene, Chattian
Counties: Brazoria County, Texas ; Also reported from Mexico (Jackson, 1937).
DESCRIPTION
TOP: Length, width, height: 63.5 mm × 54.7 mm × 14.3 mm
Top shape: Test oval, but subpentagonal; slight point at unpaired ambulacrum, flat on opposite end
Widest location: Runs from 1/5th from posterior end to 2/5th from anterior end
Top domed: Upper surface low, flat except for raised apical system and ambulacra leading to it
SIDE: Ambitus: Margin evenly curved
Side shape: Upper surface low and flat
AMB: Amb shape: Paired ambulacra all about equal in length; Unpaired ambulacrum just slightly longer
Amb width: Wide, petaloid, open on ends
Amb primary zones: Poriferous zones contain pore pairs that are small and round on each inside set, elongated on each outside set
PORE PAIRS: Shape: Inner pores round; outer pores elongated
TUBERCLES: Primary tubercles: Cover entire surface; slightly larger at margin
Primary Areola shape: Areola incised on each tubercle
APICAL SYSTEM: Size / Location: Raised
Condition: Covered with matrix
PERIPROCT (ANUS): Location: Unknown
PERISTOME (MOUTH): Condition: Adoral side covered with matrix, peristome not seen
SPECIMENS STUDIED & CONDITION: Fragment 2058.2 (Texas) and NPL 894 (Mexico) studied. Specimen 2058.2 is a partial test in situ. Tyler Stoviah found a partial specimen in Damon in 1975 showing the apical system and top four petals
ETYMOLOGY: Named for the municipality of Soto la Marina (Tamaulipas, Mexico), where the type locality (San Jose de las Rusias) is located (Jackson, 1937).
REMARKS & COMPARISONS
Remarks: Clypeaster marinanus is considered by some to be a synonym of Clypeaster rogersi (Morton). The Texas specimen is assigned to C. marinanus based on the description by Jackson (1937).
Comparisons:
Plate: ClMa-10
Series: Oligocene Group: Catahoula Formation: Anahuac
Locale: Damon Mound County: Brazoria Stage: Chattian
Length: 63.5 mm Width: 54.7 mm Height: 14.3 mm
Specimens in photos: Fragment 2058.2 (Texas), NPL 894 (Mexico)
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: USNM (Likely stored at Smithsonian National Museum of Natural History, described in Proc. U.S. Nat. Mus. 84: 227-237
Locality: Mexico (Jackson, 1937).
Systematic Paleontology
CLASS: ECHINOIDEA Leske, 1778
SUBCLASS: EUECHINOIDEA Bronn, 1860
INFRACLASS: IRREGULARIA Latreille, 1825
SUPERORDER: GNATHOSTOMATA Zittel, 1879
ORDER: CLYPEASTEROIDA A. Agassiz, 1872
FAMILY: CLYPEASTERIDAE L. Agassiz, 1835
GENUS: CLYPEASTER Lamarck, 1801
SPECIES: Clypeaster marinanus Jackson, 1937
TYPE SPECIES: Clypeaster rosaceus (Linnaeus, 1758)
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Catahoula
Formations: Anahuac Formation
Stratigraphic Units: Oligocene, Chattian
Counties: Brazoria County, Texas ; Also reported from Mexico (Jackson, 1937).
DESCRIPTION
TOP: Length, width, height: 63.5 mm × 54.7 mm × 14.3 mm
Top shape: Test oval, but subpentagonal; slight point at unpaired ambulacrum, flat on opposite end
Widest location: Runs from 1/5th from posterior end to 2/5th from anterior end
Top domed: Upper surface low, flat except for raised apical system and ambulacra leading to it
SIDE: Ambitus: Margin evenly curved
Side shape: Upper surface low and flat
AMB: Amb shape: Paired ambulacra all about equal in length; Unpaired ambulacrum just slightly longer
Amb width: Wide, petaloid, open on ends
Amb primary zones: Poriferous zones contain pore pairs that are small and round on each inside set, elongated on each outside set
PORE PAIRS: Shape: Inner pores round; outer pores elongated
TUBERCLES: Primary tubercles: Cover entire surface; slightly larger at margin
Primary Areola shape: Areola incised on each tubercle
APICAL SYSTEM: Size / Location: Raised
Condition: Covered with matrix
PERIPROCT (ANUS): Location: Unknown
PERISTOME (MOUTH): Condition: Adoral side covered with matrix, peristome not seen
SPECIMENS STUDIED & CONDITION: Fragment 2058.2 (Texas) and NPL 894 (Mexico) studied. Specimen 2058.2 is a partial test in situ. Tyler Stoviah found a partial specimen in Damon in 1975 showing the apical system and top four petals
ETYMOLOGY: Named for the municipality of Soto la Marina (Tamaulipas, Mexico), where the type locality (San Jose de las Rusias) is located (Jackson, 1937).
REMARKS & COMPARISONS
Remarks: Clypeaster marinanus is considered by some to be a synonym of Clypeaster rogersi (Morton). The Texas specimen is assigned to C. marinanus based on the description by Jackson (1937).
Comparisons:
- Clypeaster rogersi (Morton): Cooke (1942) describes C. rogersi as having an oval to subpentagonal outline, low to tumid upper surface, and flattish lower surface. The apical system is central with 5 genital pores. Petals extend more than halfway to the margin and are completely closed apically but wide open distally. The peristome is central, pentagonal, with slightly swollen sides (bourrelets). Periproct is circular, located about 1/5th the distance from the margin to the peristome. Cooke notes the shape is variable but petal shape is constant.
- Differentiation: C. marinanus (Texas specimen) shares the subpentagonal shape and open petals with C. rogersi. However, Jackson (1937) distinguished marinanus from Mexican deposits. The flat upper surface described by Thompson contrasts with the "low to tumid" variation allowed in rogersi.
