Cottaldia elliotti Thompson, 2020
Plate: CoEl-10
Series: Lower Cretaceous Group: Fredericksburg Formation: Walnut
Locale: Austin County: Travis Stage: Albian
Length: 11.5 mm Height: 7.2 mm
Collection: Ed Elliott
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: NPL 94317 — Non-vertebrate Paleontology Laboratory, University of Texas
Locality: Austin, Travis County, Texas
SYNONYMY:
2016 Cottaldia olisiponensis (Forbes) Thompson: Fossil Echinoids of Texas - A Monograph of Fossil Sea Urchins, Pgs. 52-53, Plate 36.
1987 Micropedina olisiponensis (Forbes) Akers & Akers: Texas Cretaceous Echinoids, Pg. 35.
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 elliotti Thompson, 2020
TYPE SPECIES: Cottaldia benettiae (König, 1820)
DIAGNOSIS
Medium sized Cottaldia from the Walnut Formation with pronounced sunken ambulacral and sunken adradial and interradial sutures .
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Fredericksburg
Formations: Walnut Formation
Stratigraphic Units: Lower Cretaceous, Albian
Counties: Travis (Austin), Bell (Harker Heights)
Association: Found in association with Heteraster texanus .
DESCRIPTION
TOP: Length, height: 11.5 mm L ×7.2 mm H
Top shape: Round from above
Top domed: Dome shaped; point at apical system
SIDE: Ambitus: Below midpoint
Side shape: Sub-globular; rounded sides
Relief: Ambulacra raised; interambulacra raised more
AMB: Amb shape: Lanceolate, pointed; widening to ambitus, widest at ambitus, slightly narrows at peristome
Amb width: 60% size of interambulacra at ambitus
Amb arrangement: Plating trigeminate
Depression: Pore zones depressed; adradial sutures sunken
INTERAMB: Interamb plating: Compound plates, much wider than tall
Depression: Interradial sutures sunken and zigzag
PORE PAIRS: Shape: Wide
Arrangement: Uniserial; crowd at peristome
Depression: Sunken
TUBERCLES: Primary tubercles:
Ambulacra: Small, imperforate, faintly crenulate; rows irregular. At ambitus, 2 primary tubercles located near pore pairs on each compound plate .
Interambulacra: 8 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 ambulacra and interambulacra .
Coverage: Tubercles cover entire test excluding interradial, adradial, and perradial suture areas .
APICAL SYSTEM: Size: 2.34 mm
Type: Dicyclic
Genital pores: 5 genital pores
PERIPROCT (ANUS): Shape & Size: "D" shaped
PERISTOME (MOUTH): Size: 4.8 mm; slightly larger than 43% of diameter of test
Shape: Round
Lip: Notches small; broad outside of ambulacra
SPECIMENS STUDIED & CONDITION: Three specimens studied. Holotype NPL 94317. .
ETYMOLOGY: The fossil is named after Edward Elliott, an avocational paleontologist, a personal mentor of mine, and who found the echinoid .
REMARKS & COMPARISONS
Remarks: Cottaldia elliotti is distinguished from the European Cottaldia olisiponensis (often reclassified as Micropedina) by having imperforate tubercles, whereas C. olisiponensis has perforate tubercles. Lambert (1927) incorrectly synonymized Dumblea symetrica with Micropedina olisiponensis.
Comparisons:
C. rotula (Texas): C. elliotti is much larger.
C. magna (Texas): C. elliotti is smaller.
C. granulosa: C. elliotti has smaller and fewer primary tubercles, and much more pronounced interradial sutures .
Plate: CoEl-10
Series: Lower Cretaceous Group: Fredericksburg Formation: Walnut
Locale: Austin County: Travis Stage: Albian
Length: 11.5 mm Height: 7.2 mm
Collection: Ed Elliott
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: NPL 94317 — Non-vertebrate Paleontology Laboratory, University of Texas
Locality: Austin, Travis County, Texas
SYNONYMY:
2016 Cottaldia olisiponensis (Forbes) Thompson: Fossil Echinoids of Texas - A Monograph of Fossil Sea Urchins, Pgs. 52-53, Plate 36.
1987 Micropedina olisiponensis (Forbes) Akers & Akers: Texas Cretaceous Echinoids, Pg. 35.
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 elliotti Thompson, 2020
TYPE SPECIES: Cottaldia benettiae (König, 1820)
DIAGNOSIS
Medium sized Cottaldia from the Walnut Formation with pronounced sunken ambulacral and sunken adradial and interradial sutures .
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Fredericksburg
Formations: Walnut Formation
Stratigraphic Units: Lower Cretaceous, Albian
Counties: Travis (Austin), Bell (Harker Heights)
Association: Found in association with Heteraster texanus .
DESCRIPTION
TOP: Length, height: 11.5 mm L ×7.2 mm H
Top shape: Round from above
Top domed: Dome shaped; point at apical system
SIDE: Ambitus: Below midpoint
Side shape: Sub-globular; rounded sides
Relief: Ambulacra raised; interambulacra raised more
AMB: Amb shape: Lanceolate, pointed; widening to ambitus, widest at ambitus, slightly narrows at peristome
Amb width: 60% size of interambulacra at ambitus
Amb arrangement: Plating trigeminate
Depression: Pore zones depressed; adradial sutures sunken
INTERAMB: Interamb plating: Compound plates, much wider than tall
Depression: Interradial sutures sunken and zigzag
PORE PAIRS: Shape: Wide
Arrangement: Uniserial; crowd at peristome
Depression: Sunken
TUBERCLES: Primary tubercles:
Ambulacra: Small, imperforate, faintly crenulate; rows irregular. At ambitus, 2 primary tubercles located near pore pairs on each compound plate .
Interambulacra: 8 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 ambulacra and interambulacra .
Coverage: Tubercles cover entire test excluding interradial, adradial, and perradial suture areas .
APICAL SYSTEM: Size: 2.34 mm
Type: Dicyclic
Genital pores: 5 genital pores
PERIPROCT (ANUS): Shape & Size: "D" shaped
PERISTOME (MOUTH): Size: 4.8 mm; slightly larger than 43% of diameter of test
Shape: Round
Lip: Notches small; broad outside of ambulacra
SPECIMENS STUDIED & CONDITION: Three specimens studied. Holotype NPL 94317. .
ETYMOLOGY: The fossil is named after Edward Elliott, an avocational paleontologist, a personal mentor of mine, and who found the echinoid .
REMARKS & COMPARISONS
Remarks: Cottaldia elliotti is distinguished from the European Cottaldia olisiponensis (often reclassified as Micropedina) by having imperforate tubercles, whereas C. olisiponensis has perforate tubercles. Lambert (1927) incorrectly synonymized Dumblea symetrica with Micropedina olisiponensis.
Comparisons:
C. rotula (Texas): C. elliotti is much larger.
C. magna (Texas): C. elliotti is smaller.
C. granulosa: C. elliotti has smaller and fewer primary tubercles, and much more pronounced interradial sutures .
