Cottaldia magna Thompson, 2016
Plate: CoMa-10
Series: Upper Cretaceous Group: Washita Formation: Buda
Locale: Austin County: Travis Stage: Cenomanian
Length: 26.3 mm Height: 18.0 mm Width: (Not specified)
Specimen in photo: NPL 70931 (Holotype)
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: NPL 70931 - Non-vertebrate Paleontology Laboratory, University of Texas
Locality: Shoal Creek, Austin, Travis County, Texas
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Carinacea Kroh & Smith, 2010
Superorder: Echinacea Claus, 1876
Order: Uncertain/Pedinoida/Arbacioida
Family: Pedinopsidae Durham, 1966 (or Cottaldiidae)
Genus: COTTALDIA Desor, 1856
Species: Cottaldia magna Thompson, 2016
TYPE SPECIES: Cottaldia benettiae (König, 1820)
DIAGNOSIS
Large pentagonal shaped Cottaldia from the Buda formation with UNIQUE bulging interambs that create the points of the pentagonal shape. Up to 10 primary tubercles on each compound interamb plates. Uniserial pore pairs for the entire length of the ambs excluding crowding at the peristome .
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Washita
Formations: Buda Limestone
Stratigraphic Units: Upper Cretaceous, Cenomanian
Counties: Travis County
DESCRIPTION
TOP: Length, width, height: 26.3 mm L 18.0 mm H
Top shape: Pentagonal shaped; rounded bulging interambulacra form the points of the pentagon; ambulacra located at the flat sides of the pentagon
Relief: Ambulacra raised; interambulacra raised more; sunken at interradial sutures
SIDE: Ambitus: Below midpoint
Side shape: Globular; rounded ambitus
BOTTOM: Bottom shape: Level with ambulacra; interambulacra bulging on bottom
AMB: Amb shape: Lanceolate, very pointed; straight to ambitus
Amb width: Widest at ambitus; slightly narrows at peristome
Amb arrangement: Plating trigeminate
INTERAMB: Interamb width: More than twice size of ambulacra at ambitus
Interamb plating: Compound plates, much wider than tall
Sutures: Suture plating indistinct, but very noticeable because of lack of tubercles (naked zones)
PORE PAIRS: Shape: Narrow
Arrangement: Uniserial; crowd at peristome
Depression: Sunken
TUBERCLES: Primary tubercles:
Ambulacra: Small, imperforate, faintly crenulated; rows irregular. At ambitus, 3 primary tubercles located nearest pore pairs on each compound plate; center is naked .
Interambulacra: Up to 10 primary tubercles on each compound plate; rows irregular .
Primary Perforated: No
Primary Crenulate: Yes (faintly)
Primary Areola shape: Sunken
Granules: Thick granulation on entire test excluding suture areas .
APICAL SYSTEM: Size: Scar is small (5.3 mm)
Shape: Pentagonal; point of pentagon cutting into interambulacra
Condition: Apical system missing
PERIPROCT (ANUS): Condition: Unknown
PERISTOME (MOUTH): Size: 9.2 mm; slightly larger than 1/3 of diameter of test
Shape: Round, very slightly pentagonal
Lip: Notches very small, located outside of ambulacra
SPECIMENS STUDIED & CONDITION: Holotype NPL 70931 .
ETYMOLOGY: The name "magna" is Latin for "large". It is so much larger than Cottaldia rotula from the same formation .
REMARKS & COMPARISONS
Remarks: Cottaldia magna is not depressed like Cottaldia rotula. The ambulacra line up at the middle of the pentagonal shape (the flats), not on the points of the pentagonal shape as in C. rotula. Notches are very faint, whereas they are pronounced in C. rotula.
Comparisons:
Dumblea symmetrica: Resembles C. magna, but Dumblea has biserial pore pairs and ambulacra at the corners (points) of the pentagonal shape.
Cottaldia benettiae: Resembles C. magna, but C. magna has bulging interambulacra .
Plate: CoMa-10
Series: Upper Cretaceous Group: Washita Formation: Buda
Locale: Austin County: Travis Stage: Cenomanian
Length: 26.3 mm Height: 18.0 mm Width: (Not specified)
Specimen in photo: NPL 70931 (Holotype)
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: NPL 70931 - Non-vertebrate Paleontology Laboratory, University of Texas
Locality: Shoal Creek, Austin, Travis County, Texas
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Carinacea Kroh & Smith, 2010
Superorder: Echinacea Claus, 1876
Order: Uncertain/Pedinoida/Arbacioida
Family: Pedinopsidae Durham, 1966 (or Cottaldiidae)
Genus: COTTALDIA Desor, 1856
Species: Cottaldia magna Thompson, 2016
TYPE SPECIES: Cottaldia benettiae (König, 1820)
DIAGNOSIS
Large pentagonal shaped Cottaldia from the Buda formation with UNIQUE bulging interambs that create the points of the pentagonal shape. Up to 10 primary tubercles on each compound interamb plates. Uniserial pore pairs for the entire length of the ambs excluding crowding at the peristome .
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Washita
Formations: Buda Limestone
Stratigraphic Units: Upper Cretaceous, Cenomanian
Counties: Travis County
DESCRIPTION
TOP: Length, width, height: 26.3 mm L 18.0 mm H
Top shape: Pentagonal shaped; rounded bulging interambulacra form the points of the pentagon; ambulacra located at the flat sides of the pentagon
Relief: Ambulacra raised; interambulacra raised more; sunken at interradial sutures
SIDE: Ambitus: Below midpoint
Side shape: Globular; rounded ambitus
BOTTOM: Bottom shape: Level with ambulacra; interambulacra bulging on bottom
AMB: Amb shape: Lanceolate, very pointed; straight to ambitus
Amb width: Widest at ambitus; slightly narrows at peristome
Amb arrangement: Plating trigeminate
INTERAMB: Interamb width: More than twice size of ambulacra at ambitus
Interamb plating: Compound plates, much wider than tall
Sutures: Suture plating indistinct, but very noticeable because of lack of tubercles (naked zones)
PORE PAIRS: Shape: Narrow
Arrangement: Uniserial; crowd at peristome
Depression: Sunken
TUBERCLES: Primary tubercles:
Ambulacra: Small, imperforate, faintly crenulated; rows irregular. At ambitus, 3 primary tubercles located nearest pore pairs on each compound plate; center is naked .
Interambulacra: Up to 10 primary tubercles on each compound plate; rows irregular .
Primary Perforated: No
Primary Crenulate: Yes (faintly)
Primary Areola shape: Sunken
Granules: Thick granulation on entire test excluding suture areas .
APICAL SYSTEM: Size: Scar is small (5.3 mm)
Shape: Pentagonal; point of pentagon cutting into interambulacra
Condition: Apical system missing
PERIPROCT (ANUS): Condition: Unknown
PERISTOME (MOUTH): Size: 9.2 mm; slightly larger than 1/3 of diameter of test
Shape: Round, very slightly pentagonal
Lip: Notches very small, located outside of ambulacra
SPECIMENS STUDIED & CONDITION: Holotype NPL 70931 .
ETYMOLOGY: The name "magna" is Latin for "large". It is so much larger than Cottaldia rotula from the same formation .
REMARKS & COMPARISONS
Remarks: Cottaldia magna is not depressed like Cottaldia rotula. The ambulacra line up at the middle of the pentagonal shape (the flats), not on the points of the pentagonal shape as in C. rotula. Notches are very faint, whereas they are pronounced in C. rotula.
Comparisons:
Dumblea symmetrica: Resembles C. magna, but Dumblea has biserial pore pairs and ambulacra at the corners (points) of the pentagonal shape.
Cottaldia benettiae: Resembles C. magna, but C. magna has bulging interambulacra .
