Gauthieria parva Thompson, 2016
Plate: GaPa-10
Series: Upper Cretaceous Group: Austin Formation: Austin Chalk
Locale: San Antonio County: Bexar Stage: Santonian
Length: 16.6 mm Width: 6.8 mm
Specimen in photo: NPL 82983 (Holotype)
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: NPL 82983 — Non-vertebrate Paleontology Laboratory, University of Texas
Locality: San Antonio, Bexar County, Texas
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Carinacea Kroh & Smith, 2010
Superorder: Calycina Gregory, 1900
Order: Phymosomatoida Mortensen, 1904
Family: Phymosomatidae Haime in d'Archiac & Haime, 1853
Genus: GAUTHIERIA Lambert, 1888
Species: Gauthieria parva Thompson, 2016
TYPE SPECIES: Cyphosoma radiatum (Sorignet, 1850)
DIAGNOSIS
A Gauthieria from the Upper Cretaceous, Austin Chalk Formation of Texas with faint tubercles that lack any radial striation on the areole and bosses.
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Austin
Formations: Austin Chalk
Stratigraphic Units: Upper Cretaceous, Santonian
Counties: Bexar County
DESCRIPTION
TOP: Width, height: 16.6 mm W × 6.8 mm H
Top shape: Round from above
Convexity: Depressed profile
SIDE: Ambitus: 50% from base
Side shape: Inflated
BOTTOM: Bottom flat: Flat
Bottom shape: Depressed base
SIZE: Range: Width 16.6 mm to 7.8 mm
AMB: Amb primary tubercles: Two alternating rows of 9 tubercles; one primary tubercle per plate
Amb plating: Pentagonal; wider than tall
INTERAMB: Interamb width: 1.3 times wider than ambulacra
Interamb plating: Plates 2 times wider than amb plates
Interamb primary tubercles: Two rows of 8 to 9 tubercles
Sutures: Interradial suture pronounced
PORE PAIRS: Arrangement: Uniserial; slight zigzag pattern
Geminate count: 5 pore pair sets per amb plate
TUBERCLES: Primary Perforated: No
Primary Crenulate: Yes
Primary Boss: Without radial striation
Primary Mamelon: Subdued
Size: Faint; larger in interambulacra
Secondary tubercles: Faint scrobicular tubercles surround primary tubercles on both ambs and interambs
Granules: Granulation runs vertically along adradial suture; zigzag pattern along interradial and perradial sutures. Less granulation near apical system and near peristome .
APICAL SYSTEM: Size: Scar 42% of diameter of test
Shape: Pentagonal; points toward interambs, extends slightly into posterior interamb
PERIPROCT (ANUS): Unknown
PERISTOME (MOUTH): Size: 36% of diameter of test
Lip: Buccal notches present but faint
Phyllodes: No phyllodes
SPECIMENS STUDIED & CONDITION
Holotype NPL 82983 .
ETYMOLOGY: Named after the Latin word for small (parva) .
REMARKS & COMPARISONS
Remarks: Gauthieria parva differs from the type species Gauthieria radiata. The apical system cuts less into the posterior interambulacrum and the notches are less pronounced than in G. radiata. The lack of striation on the aboral areole and bosses sets it apart from most Gauthieria species .
Plate: GaPa-10
Series: Upper Cretaceous Group: Austin Formation: Austin Chalk
Locale: San Antonio County: Bexar Stage: Santonian
Length: 16.6 mm Width: 6.8 mm
Specimen in photo: NPL 82983 (Holotype)
Repository: Non-vertebrate Paleo. Lab., Univ. of Texas
HOLOTYPE INFO:
Holotype: NPL 82983 — Non-vertebrate Paleontology Laboratory, University of Texas
Locality: San Antonio, Bexar County, Texas
SYSTEMATIC PALEONTOLOGY – TAXONOMY
Class: Echinoidea Leske, 1778
Subclass: Euechinoidea Bronn, 1860
Infraclass: Carinacea Kroh & Smith, 2010
Superorder: Calycina Gregory, 1900
Order: Phymosomatoida Mortensen, 1904
Family: Phymosomatidae Haime in d'Archiac & Haime, 1853
Genus: GAUTHIERIA Lambert, 1888
Species: Gauthieria parva Thompson, 2016
TYPE SPECIES: Cyphosoma radiatum (Sorignet, 1850)
DIAGNOSIS
A Gauthieria from the Upper Cretaceous, Austin Chalk Formation of Texas with faint tubercles that lack any radial striation on the areole and bosses.
STRATIGRAPHICAL OCCURRENCE & DISTRIBUTION
Group: Austin
Formations: Austin Chalk
Stratigraphic Units: Upper Cretaceous, Santonian
Counties: Bexar County
DESCRIPTION
TOP: Width, height: 16.6 mm W × 6.8 mm H
Top shape: Round from above
Convexity: Depressed profile
SIDE: Ambitus: 50% from base
Side shape: Inflated
BOTTOM: Bottom flat: Flat
Bottom shape: Depressed base
SIZE: Range: Width 16.6 mm to 7.8 mm
AMB: Amb primary tubercles: Two alternating rows of 9 tubercles; one primary tubercle per plate
Amb plating: Pentagonal; wider than tall
INTERAMB: Interamb width: 1.3 times wider than ambulacra
Interamb plating: Plates 2 times wider than amb plates
Interamb primary tubercles: Two rows of 8 to 9 tubercles
Sutures: Interradial suture pronounced
PORE PAIRS: Arrangement: Uniserial; slight zigzag pattern
Geminate count: 5 pore pair sets per amb plate
TUBERCLES: Primary Perforated: No
Primary Crenulate: Yes
Primary Boss: Without radial striation
Primary Mamelon: Subdued
Size: Faint; larger in interambulacra
Secondary tubercles: Faint scrobicular tubercles surround primary tubercles on both ambs and interambs
Granules: Granulation runs vertically along adradial suture; zigzag pattern along interradial and perradial sutures. Less granulation near apical system and near peristome .
APICAL SYSTEM: Size: Scar 42% of diameter of test
Shape: Pentagonal; points toward interambs, extends slightly into posterior interamb
PERIPROCT (ANUS): Unknown
PERISTOME (MOUTH): Size: 36% of diameter of test
Lip: Buccal notches present but faint
Phyllodes: No phyllodes
SPECIMENS STUDIED & CONDITION
Holotype NPL 82983 .
ETYMOLOGY: Named after the Latin word for small (parva) .
REMARKS & COMPARISONS
Remarks: Gauthieria parva differs from the type species Gauthieria radiata. The apical system cuts less into the posterior interambulacrum and the notches are less pronounced than in G. radiata. The lack of striation on the aboral areole and bosses sets it apart from most Gauthieria species .
