taxonID	type	format	identifier	references	title	description	created	creator	contributor	publisher	audience	source	license	rightsHolder	datasetID
CC63253534526E43FEABE771FB02F9E0.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/20849628/files/figure.png	https://doi.org/10.5281/zenodo.20849628	FIG. 1. — Degeneraster spenceri n. gen.,n. sp., holotype AA.IST.OS.62,artificial casts;Euaxosida: A-E, aboral views:A, B, E entire remnant,the breakage surface serving to orient images, B, E, oblique views; C, arm to SW of A; D, arm to NW of A. Distal arm intervals pass out of plane of focus in inclined views. The central disk collapsed into the interior, specimen distortion from original life shape appearing limited. Abactinals are uniform if somewhat irregular and appear to have overlapped slightly, overlap perhaps enhanced with preservation. Configuration of the disk might suggest some minor differentiation of centrale and an aboral circlet (A, arrow at possible ring margin). Any alignment of abactinals in rows is minor, and no views suggest presence of an ambital framework.Scattered dark spots might represent papular pores, alternatively these might be preservational irregularities; F, oral aspect, closely appressed mouth-angle ossicles (MAO) and axials indicate specimen is little distorted and flattened from life configuration; extraxials irregular, small, inferomarginals not differentiated; madreporite in upper interbrachium; G, granular madreporite surface similar to that of Chinianaster (Blake & Lefebvre 2025: fig. 3A, B) and differing from those typical of most asteroids (e.g., Fig. 5E). Scale bars: A, B, E, F, 5 mm; C, D, 3 mm; G, 1 mm.	FIG. 1. — Degeneraster spenceri n. gen.,n. sp., holotype AA.IST.OS.62,artificial casts;Euaxosida: A-E, aboral views:A, B, E entire remnant,the breakage surface serving to orient images, B, E, oblique views; C, arm to SW of A; D, arm to NW of A. Distal arm intervals pass out of plane of focus in inclined views. The central disk collapsed into the interior, specimen distortion from original life shape appearing limited. Abactinals are uniform if somewhat irregular and appear to have overlapped slightly, overlap perhaps enhanced with preservation. Configuration of the disk might suggest some minor differentiation of centrale and an aboral circlet (A, arrow at possible ring margin). Any alignment of abactinals in rows is minor, and no views suggest presence of an ambital framework.Scattered dark spots might represent papular pores, alternatively these might be preservational irregularities; F, oral aspect, closely appressed mouth-angle ossicles (MAO) and axials indicate specimen is little distorted and flattened from life configuration; extraxials irregular, small, inferomarginals not differentiated; madreporite in upper interbrachium; G, granular madreporite surface similar to that of Chinianaster (Blake & Lefebvre 2025: fig. 3A, B) and differing from those typical of most asteroids (e.g., Fig. 5E). Scale bars: A, B, E, F, 5 mm; C, D, 3 mm; G, 1 mm.	2026-06-24	Blake, Daniel B.;Lefebvre, Bertrand		Zenodo	biologists	Blake, Daniel B.;Lefebvre, Bertrand			
CC63253534526E43FEABE771FB02F9E0.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/20849630/files/figure.png	https://doi.org/10.5281/zenodo.20849630	FIG. 2. — Degeneraster spenceri n. gen., n. sp., artificial casts, Euaxosidea Blake, 2018: A-E, paratype AA.IST.OS.34: A, entire remnant, madreporite (arrow); B, disk area; closely abutted mouth-angle ossicles (MAO) indicate only minor burial distortion; ossicles unlike abactinals (Fig. 1) arguing actinal differentiation; adaxial of D (arrow); C, MAO configuration, torus lacking, linear series of spots (upper arrow) might identify MAO spinelet bases; madreporite (lower arrow); D, NW arm of A, no differentiated marginal series in evidence; interbrachial ossicles plate-like, arm ossicles granular, neither series similar to abactinals; axials equidimensional,podial basins large,shared by successive axials;axials longitudinally abutted,not overlapping (left arrow); axials and adaxials slightly displaced, not overlapping significantly (lower right arrow); adaxials T-shaped with a stem extended toward the axial; spine base medial (lower right arrow);adradial adaxial margins rounded for podia; E, NE arm tip of A, terminal not recognized; podial depressions suggest podial pores, see Discussion; F, G, paratype AA.IST.OS.59, oral view; F, entire remnant; G, mouth frame partially distended, axial exposure and shadows indicate arms retain asteroid ambulacral furrow; madreporite not recognized but likely obscured. Scale bars: A, B, F, G, 5 mm; C-E, 2 mm.	FIG. 2. — Degeneraster spenceri n. gen., n. sp., artificial casts, Euaxosidea Blake, 2018: A-E, paratype AA.IST.OS.34: A, entire remnant, madreporite (arrow); B, disk area; closely abutted mouth-angle ossicles (MAO) indicate only minor burial distortion; ossicles unlike abactinals (Fig. 1) arguing actinal differentiation; adaxial of D (arrow); C, MAO configuration, torus lacking, linear series of spots (upper arrow) might identify MAO spinelet bases; madreporite (lower arrow); D, NW arm of A, no differentiated marginal series in evidence; interbrachial ossicles plate-like, arm ossicles granular, neither series similar to abactinals; axials equidimensional,podial basins large,shared by successive axials;axials longitudinally abutted,not overlapping (left arrow); axials and adaxials slightly displaced, not overlapping significantly (lower right arrow); adaxials T-shaped with a stem extended toward the axial; spine base medial (lower right arrow);adradial adaxial margins rounded for podia; E, NE arm tip of A, terminal not recognized; podial depressions suggest podial pores, see Discussion; F, G, paratype AA.IST.OS.59, oral view; F, entire remnant; G, mouth frame partially distended, axial exposure and shadows indicate arms retain asteroid ambulacral furrow; madreporite not recognized but likely obscured. Scale bars: A, B, F, G, 5 mm; C-E, 2 mm.	2026-06-24	Blake, Daniel B.;Lefebvre, Bertrand		Zenodo	biologists	Blake, Daniel B.;Lefebvre, Bertrand			
CC63253534526E43FEABE771FB02F9E0.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/20849632/files/figure.png	https://doi.org/10.5281/zenodo.20849632	FIG. 3. — Diverse Somasteroidea Spencer, 1951 (A-D) and Euaxosida (E-H); A, B, and G are artificial casts, others are original specimens: A, Chinianaster levyi Thoral, 1935, Saint-Chinian Formation, Early Ordovician (late Tremadocian); Montagne Noire; UCBL-FSL 712003, oral view, axials of left ambulacrum abut at mouth frame as in life, dilated in ambulacrum to right to yield an artifactual “buccal slit”; radial channel closed orally by a shield-like skeletal arch, the transverse ridge flaring abradially to abut virgal series (left arrow); disrupted virgalia arise at oral frame (right arrow) thereby perhaps contributing to the view that the first axial series was deflected to form the inferomarginal series (Spencer 1951; Spencer & Wright 1966). B, Cantabrigiaster fezouataensis Hunter & Ortega-Hernández, Fezouata Formation,Early Ordovician (late Tremadocian);Zagora area,Central Anti-Atlas,Morocco;holotype UCBL-FSL 424961,oral view,enlarged and flattened radial water-vascular channel exposes large aboral surface,axials both paired and offset along arm midline (arrow); axial intervals beyond radial channel boundary equidimensional and approximately bilateral; adaxials robust, abutted to form platform; C, D, Ophioxenikos langenheimi Blake & Guensburg, Lower Pogonip Group,Early Ordovician (late early to middle Floian); Ely Springs Mountain Range, south-central Nevada,United States;holotype UI–X–4751,oral views:C, entire specimen, disk dilated, granular abactinals and darkened circular abactinal “footprints” exposed within mouth frame, axial series dilated proximally, remaining closed distally; mouth-angle ossicles (MAO) pair (abutted arrow pair), MAO little differentiated from and aligned with subsequent axials; adaxial series deflected to form platform like configuration at disk (left arrow), virgalia appearing less robust, perhaps separated in life (upper right arrow); D, mouth frame and adjacent axial series; MAO pair (medial arrow), abactinals and abactinal “footprint” beyond; shared skeletally closed podial basin (left arrow); adaxial series near mouth frame not suggesting a platform (right arrow); E, F, Jugiaster specious (Miller & Dyer, 1878), CMC P50629, specimen locality data lost, oral views: E, most of remnant, axial form similar to that of somasteroids but radial water-vascular channel proportionately smaller, adaxials and inferomarginals extend laterally in a convergent configuration suggestive of virgalia;F, axials weakly displaced but articulate at a small point (arrow) suggesting plesiomorphic flexibility;podial basins closed but adaxial curvature suggests podial tissues extended laterally, an apparent skeletal discontinuity at least suggesting a podial pore; G, Petraster kinihani (Baily, 1879), Ballymoney Group (Sandbian; see Donovan et al. 1996), near Bannow, County Wexford, Ireland; GSI/F 00084, oral view, distal right, flattened arm interval, small water vascular channel dilated, axial interval beyond radial channel bilateral, approximately equidimensional, in that similar to A-F; water channel ridge distal to right of transverse ridge depressed relative to that to left marking transverse water-vascular channel; transverse ridge abutment with adaxial small point (arrow) marking weak euaxosidan vaulting and suggesting retention of potential lateral flexure as in somasteroids; adaxial curvature suggests ossicles bordered soft tissues as F; H, Estoniaster maennili Blake & Rozhnov,Late Ordovician (late Sandbian, upper part of the Didymograptus multidens Zone), Vasalemma Quarry, near Tallinn, northern Estonia; PIN 4125/766, oral view of adradial termini of axials, cross-furrow articular faceting clear but weak, transverse channel to podial basin (arrow) on ossicular surface, not obscured between successive axials as in derived orders (Fig. 4D). Scale bars: A, C, D, F-H, 3 mm; B, E, 5 mm.	FIG. 3. — Diverse Somasteroidea Spencer, 1951 (A-D) and Euaxosida (E-H); A, B, and G are artificial casts, others are original specimens: A, Chinianaster levyi Thoral, 1935, Saint-Chinian Formation, Early Ordovician (late Tremadocian); Montagne Noire; UCBL-FSL 712003, oral view, axials of left ambulacrum abut at mouth frame as in life, dilated in ambulacrum to right to yield an artifactual “buccal slit”; radial channel closed orally by a shield-like skeletal arch, the transverse ridge flaring abradially to abut virgal series (left arrow); disrupted virgalia arise at oral frame (right arrow) thereby perhaps contributing to the view that the first axial series was deflected to form the inferomarginal series (Spencer 1951; Spencer & Wright 1966). B, Cantabrigiaster fezouataensis Hunter & Ortega-Hernández, Fezouata Formation,Early Ordovician (late Tremadocian);Zagora area,Central Anti-Atlas,Morocco;holotype UCBL-FSL 424961,oral view,enlarged and flattened radial water-vascular channel exposes large aboral surface,axials both paired and offset along arm midline (arrow); axial intervals beyond radial channel boundary equidimensional and approximately bilateral; adaxials robust, abutted to form platform; C, D, Ophioxenikos langenheimi Blake & Guensburg, Lower Pogonip Group,Early Ordovician (late early to middle Floian); Ely Springs Mountain Range, south-central Nevada,United States;holotype UI–X–4751,oral views:C, entire specimen, disk dilated, granular abactinals and darkened circular abactinal “footprints” exposed within mouth frame, axial series dilated proximally, remaining closed distally; mouth-angle ossicles (MAO) pair (abutted arrow pair), MAO little differentiated from and aligned with subsequent axials; adaxial series deflected to form platform like configuration at disk (left arrow), virgalia appearing less robust, perhaps separated in life (upper right arrow); D, mouth frame and adjacent axial series; MAO pair (medial arrow), abactinals and abactinal “footprint” beyond; shared skeletally closed podial basin (left arrow); adaxial series near mouth frame not suggesting a platform (right arrow); E, F, Jugiaster specious (Miller & Dyer, 1878), CMC P50629, specimen locality data lost, oral views: E, most of remnant, axial form similar to that of somasteroids but radial water-vascular channel proportionately smaller, adaxials and inferomarginals extend laterally in a convergent configuration suggestive of virgalia;F, axials weakly displaced but articulate at a small point (arrow) suggesting plesiomorphic flexibility;podial basins closed but adaxial curvature suggests podial tissues extended laterally, an apparent skeletal discontinuity at least suggesting a podial pore; G, Petraster kinihani (Baily, 1879), Ballymoney Group (Sandbian; see Donovan et al. 1996), near Bannow, County Wexford, Ireland; GSI/F 00084, oral view, distal right, flattened arm interval, small water vascular channel dilated, axial interval beyond radial channel bilateral, approximately equidimensional, in that similar to A-F; water channel ridge distal to right of transverse ridge depressed relative to that to left marking transverse water-vascular channel; transverse ridge abutment with adaxial small point (arrow) marking weak euaxosidan vaulting and suggesting retention of potential lateral flexure as in somasteroids; adaxial curvature suggests ossicles bordered soft tissues as F; H, Estoniaster maennili Blake & Rozhnov,Late Ordovician (late Sandbian, upper part of the Didymograptus multidens Zone), Vasalemma Quarry, near Tallinn, northern Estonia; PIN 4125/766, oral view of adradial termini of axials, cross-furrow articular faceting clear but weak, transverse channel to podial basin (arrow) on ossicular surface, not obscured between successive axials as in derived orders (Fig. 4D). Scale bars: A, C, D, F-H, 3 mm; B, E, 5 mm.	2026-06-24	Blake, Daniel B.;Lefebvre, Bertrand		Zenodo	biologists	Blake, Daniel B.;Lefebvre, Bertrand			
CC63253534526E43FEABE771FB02F9E0.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/20849640/files/figure.png	https://doi.org/10.5281/zenodo.20849640	FIG. 5. — Diverse early Asterozoa, all but I and J are original specimens: A, Hudsonaster? sp., Hadrosida, Decorah Shale, Trenton Group, Middle Ordovician, Minneapolis, Minnesota, United States; CMC IP36520, oral view. Geologic data from a label identify it originally as a Ward’s Natural Science Establishment assigning the specimen to Hudsonaster narrawayi (Hudson, 1912), the overall shape and presence of actinals would be atypical of Hudsonaster. The irregular development of actinals (arrow) suggests a secondary, space-filling genesis; B, Aerliceaster nexosus Blake et al., 2020b, Euaxosida, Garden City Formation, Early to Middle Ordovician, Bear River Range, Franklin County, Idaho; holotype IMNH IP-276/850, oral view, the mouth frame is weakly distended and the ambulacra variously flattened to expose the aboral surfaces of the axials. Axillaries are varied in shape and positioning (arrows), in one interbrachium (lower arrow) two ossicles “competing” as the axillary. Within the marginal frame, actinals variously developed suggesting an early stage of differentiation; C, Jugiaster speciosus (Miller & Dyer, 1878), Euaxosida, MUGM T-565, Waynesville Formation, Late Ordovician, Indiana, oral view, abundant somewhat irregularly arranged actinals lie within the marginal framework; lower left arm regenerating at time of death; D, E, Estoniaster maennili Blake & Rozhnov, 2007, Euaxosida, Late Ordovician (late Sandbian, upper part of the Didymograptus multidens Zone), Vasalemma Quarry, near Tallinn, northern Estonia; PIN 4125/766: D, aboral view, abactinals are closely fitted and granular, not appearing differentiated into series and in that similar to those of Ophioxenikos (Fig. 3C); shield-like laterally abutted axials that are common among early Asterozoa; E, madreporite (at arrow, D), radiating ridge-and-groove configuration is common among younger asteroids and unlike the granular texture of D. spenceri n. gen., n. sp. (Figs 1G; 2A). F, Eukrinaster ibexensis Blake, Guensburg, Sprinkle & Sumrall, 2007, Euaxosida, upper Fillmore Formation, Ibex area, west-central Utah, zone J, early middle Arenig (Floian), Early Ordovician; paratype TMM 1965TX11, aboral view, disk is large and bordered by well-defined marginal series (arrow); both abactinals and axials are similar to those of basal Ophioxenikos and E. maennili (D); G, H, Eriaster ibexensis Blake & Guensburg,2005, Hadrosida, Fillmore Limestone, G-2 trilobite zone, equivalent to the very top of the Tremadocian, Early Ordovician; Ibex area, western Utah; FMNH PE 52741: G, extraxial abactinal morphology clearly differentiated in a very early asteroid, unlike those of both Somasteroidea and D. spenceri n. gen., n. sp.; carinal series remains only distal to the arrow; H, poorly preserved adaxial shape identifies ordinal assignment; I, J, Componaster spurius Glass et al., Ophiuroidea,Tizi n’Mourghi (Cricket’s Pass),eastern Anti-Atlas,Morocco;Lower Ktaoua Formation,Upper Ordovician (lower Katian):I, paratype AA.TNMb.OS.28, aboral view, see Discussion; J, holotype MHNM.15690.113, oral view, see Discussion; K, Falloaster anquiroisitus Blake, Gahn & Guensburg, 2020a; IMNH IP- 276/849,class unassigned,Garden City Formation,Early Ordovician,(Floian/Blackhillsian),Bear River Range,Bear Lake County,Idaho;the only known specimen of an aberrant asterozoan not assigned at the class level, outcrop weathering differentially exposing arms, the disk obscured. An arm is deeply weathered as to exposed large podial pores (middle arrow). Only the aboral surface has been largely lost on a second arm to expose a large, plate-like abactinal (right arrow) and vaulted axials with unique transverse ribbing. Madreporite is lateral (left arrow). Scale bars: A-C, 5 mm; D, F, 10 mm; E, 1 mm; G-K, 3mm.	FIG. 5. — Diverse early Asterozoa, all but I and J are original specimens: A, Hudsonaster? sp., Hadrosida, Decorah Shale, Trenton Group, Middle Ordovician, Minneapolis, Minnesota, United States; CMC IP36520, oral view. Geologic data from a label identify it originally as a Ward’s Natural Science Establishment assigning the specimen to Hudsonaster narrawayi (Hudson, 1912), the overall shape and presence of actinals would be atypical of Hudsonaster. The irregular development of actinals (arrow) suggests a secondary, space-filling genesis; B, Aerliceaster nexosus Blake et al., 2020b, Euaxosida, Garden City Formation, Early to Middle Ordovician, Bear River Range, Franklin County, Idaho; holotype IMNH IP-276/850, oral view, the mouth frame is weakly distended and the ambulacra variously flattened to expose the aboral surfaces of the axials. Axillaries are varied in shape and positioning (arrows), in one interbrachium (lower arrow) two ossicles “competing” as the axillary. Within the marginal frame, actinals variously developed suggesting an early stage of differentiation; C, Jugiaster speciosus (Miller & Dyer, 1878), Euaxosida, MUGM T-565, Waynesville Formation, Late Ordovician, Indiana, oral view, abundant somewhat irregularly arranged actinals lie within the marginal framework; lower left arm regenerating at time of death; D, E, Estoniaster maennili Blake & Rozhnov, 2007, Euaxosida, Late Ordovician (late Sandbian, upper part of the Didymograptus multidens Zone), Vasalemma Quarry, near Tallinn, northern Estonia; PIN 4125/766: D, aboral view, abactinals are closely fitted and granular, not appearing differentiated into series and in that similar to those of Ophioxenikos (Fig. 3C); shield-like laterally abutted axials that are common among early Asterozoa; E, madreporite (at arrow, D), radiating ridge-and-groove configuration is common among younger asteroids and unlike the granular texture of D. spenceri n. gen., n. sp. (Figs 1G; 2A). F, Eukrinaster ibexensis Blake, Guensburg, Sprinkle & Sumrall, 2007, Euaxosida, upper Fillmore Formation, Ibex area, west-central Utah, zone J, early middle Arenig (Floian), Early Ordovician; paratype TMM 1965TX11, aboral view, disk is large and bordered by well-defined marginal series (arrow); both abactinals and axials are similar to those of basal Ophioxenikos and E. maennili (D); G, H, Eriaster ibexensis Blake & Guensburg,2005, Hadrosida, Fillmore Limestone, G-2 trilobite zone, equivalent to the very top of the Tremadocian, Early Ordovician; Ibex area, western Utah; FMNH PE 52741: G, extraxial abactinal morphology clearly differentiated in a very early asteroid, unlike those of both Somasteroidea and D. spenceri n. gen., n. sp.; carinal series remains only distal to the arrow; H, poorly preserved adaxial shape identifies ordinal assignment; I, J, Componaster spurius Glass et al., Ophiuroidea,Tizi n’Mourghi (Cricket’s Pass),eastern Anti-Atlas,Morocco;Lower Ktaoua Formation,Upper Ordovician (lower Katian):I, paratype AA.TNMb.OS.28, aboral view, see Discussion; J, holotype MHNM.15690.113, oral view, see Discussion; K, Falloaster anquiroisitus Blake, Gahn & Guensburg, 2020a; IMNH IP- 276/849,class unassigned,Garden City Formation,Early Ordovician,(Floian/Blackhillsian),Bear River Range,Bear Lake County,Idaho;the only known specimen of an aberrant asterozoan not assigned at the class level, outcrop weathering differentially exposing arms, the disk obscured. An arm is deeply weathered as to exposed large podial pores (middle arrow). Only the aboral surface has been largely lost on a second arm to expose a large, plate-like abactinal (right arrow) and vaulted axials with unique transverse ribbing. Madreporite is lateral (left arrow). Scale bars: A-C, 5 mm; D, F, 10 mm; E, 1 mm; G-K, 3mm.	2026-06-24	Blake, Daniel B.;Lefebvre, Bertrand		Zenodo	biologists	Blake, Daniel B.;Lefebvre, Bertrand			
CC63253534526E43FEABE771FB02F9E0.taxon	http://purl.org/dc/dcmitype/StillImage	image/png	https://zenodo.org/record/20849634/files/figure.png	https://doi.org/10.5281/zenodo.20849634	FIG. 4. —Differentiation of ambulacral construction among Euaxosida Blake,2018 (A, B), Hadrosida Blake,2018 (C-E), and Kermasida Blake,2018 (F-H); all original specimens: A, B, “Palaeaster” exculptus (Miller, 1881), Richmond Formation, Late Ordovician (Richmondian, Katian), near Waynesville, Ohio, United States, USNM 60608:A, specimen remnant,relatively weakly articulated axial/adaxial series and low-arched ambulacra flattened to expose full axial breadth,as is typical of Euaxosida; arrow identifies site of (B); B, mouth-angle ossicles (MAO) pair flattened, each bearing multiple axials, see text; C-E, Anthroosasterias stibareus Blake, Gilmore City Formation, Early Carboniferous (Kinderhookian,Tournaisian),Gilmore City, Iowa, United States, USNM 611002:C, aboral view, disk vaulted, differentiated ossicles likly indicate an aboral circlet; carinal series, marginals on arms; lateral abactinals aligned; D, oral view of remnant, actinostome vaulted; E, transverse view of arm; position of axial/adaxial contact (D, arrow), axials displaced more aborally onto adaxials than in a euaxosidan (Figs 1-3E-G) to form a stronger, deeper furrow; F-H, Delicaster enigmaticus (Kesling), Paint Creek Formation, late early Carboniferous (Chesterian), St. Clair County, Illinois, United States, UMMP 54262: F, lateral view of arm, large marginals to right; proportionately small axials (arrow) fully vaulted onto adaxials, axials abutted laterally, podial pores present; G, ambulacral groove closed as is typical of kermasidan preservation, MAO closely arranged around mouth opening; madreporite (arrow) appears lateral but might be displaced from life position; H, aboral view, disk ossicles robust and enlarged relative to arm granular abutted abactinals; carinals not developed. Scale bars: A, C, D, 10 mm; B, E, F-H, 3 mm.	FIG. 4. —Differentiation of ambulacral construction among Euaxosida Blake,2018 (A, B), Hadrosida Blake,2018 (C-E), and Kermasida Blake,2018 (F-H); all original specimens: A, B, “Palaeaster” exculptus (Miller, 1881), Richmond Formation, Late Ordovician (Richmondian, Katian), near Waynesville, Ohio, United States, USNM 60608:A, specimen remnant,relatively weakly articulated axial/adaxial series and low-arched ambulacra flattened to expose full axial breadth,as is typical of Euaxosida; arrow identifies site of (B); B, mouth-angle ossicles (MAO) pair flattened, each bearing multiple axials, see text; C-E, Anthroosasterias stibareus Blake, Gilmore City Formation, Early Carboniferous (Kinderhookian,Tournaisian),Gilmore City, Iowa, United States, USNM 611002:C, aboral view, disk vaulted, differentiated ossicles likly indicate an aboral circlet; carinal series, marginals on arms; lateral abactinals aligned; D, oral view of remnant, actinostome vaulted; E, transverse view of arm; position of axial/adaxial contact (D, arrow), axials displaced more aborally onto adaxials than in a euaxosidan (Figs 1-3E-G) to form a stronger, deeper furrow; F-H, Delicaster enigmaticus (Kesling), Paint Creek Formation, late early Carboniferous (Chesterian), St. Clair County, Illinois, United States, UMMP 54262: F, lateral view of arm, large marginals to right; proportionately small axials (arrow) fully vaulted onto adaxials, axials abutted laterally, podial pores present; G, ambulacral groove closed as is typical of kermasidan preservation, MAO closely arranged around mouth opening; madreporite (arrow) appears lateral but might be displaced from life position; H, aboral view, disk ossicles robust and enlarged relative to arm granular abutted abactinals; carinals not developed. Scale bars: A, C, D, 10 mm; B, E, F-H, 3 mm.	2026-06-24	Blake, Daniel B.;Lefebvre, Bertrand		Zenodo	biologists	Blake, Daniel B.;Lefebvre, Bertrand			
