Europacantha paciphila, Thuy, 2013

Thuy, Ben, 2013, Temporary expansion to shelf depths rather than an onshore-offshore trend: the shallow-water rise and demise of the modern deep-sea brittle star family Ophiacanthidae (Echinodermata: Ophiuroidea), European Journal of Taxonomy 48, pp. 1-242 : 97-98

Europacantha paciphila sp. nov.

urn:lsid:zoobank.org:act:96307602-8F71-4187-B901-312179D4E69C

Fig. 18 : 3-4

Diagnosis

As for genus.

Etymology

Name derived from pax, Latin for “peace”, and Philia, Greek for “love”, in reference to peace prevailing between nations in Europe, against all nationalist odds.

Type material

Holotype

MHI 2090/1 .

Paratype

MHI 2091/1.

Type locality and horizon

Felsöörs, Hungary; Felsöörs Formation, late Anisian, Middle Triassic.

Additional material

MHI 2092/1-6 (6 dissociated LAPs).

Description

Holotype

MHI 2090/1 is a dissociated, small, median to proximal LAP; approximately 1.5 times higher than wide; rather stout, trapezoid aspect; dorsal edge oblique, very weakly concave as a result of a constriction; distal edge gently convex; proximal edge irregularly concave, with small, round, non-prominent central protrusion; outer surface with finely meshed stereom, devoid of vertical striation or other conspicuous elements of ornament elements. Five large, equi-distant, ear-shaped spine articulations freestanding on strongly elevated distal portion of LAP; ventral and dorsal lobes merged into continuous volute; dorsal lobe larger than ventral one, thickened; dorsalward increase in size of spine articulations; gap between spine articulations and distal edge of LAP narrow; spine articulations not bordered proximally by a ridge-like structure. Ventral edge of LAP oblique, very gently convex.

Inner side of LAP with sharply defined, prominent, relatively broad, oblique, gently proximally bent ridge; ventral half of ridge most strongly prominent; not merged with ventral portion fo LAP; dorsal half of ridge widening dorsalwards, with short, ventrally pointing extension; inner side of distal edge of LAP devoid of spurs; inner side of tentacle notch relatively small, shallow, moderately well defined laterally. Very shallow, poorly defined vertical ridge dorsally bordering tentacle notch.

Paratype supplements and variation

MHI 2091/1 is a dissociated proximal LAP; almost twice higher than wide; ventro-proximal tip fragmentary; slightly less stout than holotype; single small, slightly protruding and very weakly prominent spur in the middle of the proximal edge. Six spine articulations on strongly elevated distal portion of LAP, poorly preserved but apparently similar to those observed on holotype; spine articulations not sharply bordered proximally by a ridge-like structure.

Inner side of LAP poorly preserved and partly obscured by sediment; ridge not clearly discernible, probably gently proximally bent as in holotype, with widened, near-triangular dorsal tip displaying a very short ventrally pointing extension; no spurs on inner side of distal edge of LAP; inner side of tentacle notch poorly preserved, small. Very shallow, poorly preserved vertical furrow with two or three small, widely spaced perforations, dorsally bordering tentacle notch.

Remarks

Since these LAP type is the only one assigned to Europacantha gen. nov., its systematic affinities are discussed above.

Occurrence

Late Anisian of Hungary.

Figures

Fig. 18. Fossil lateral arm plates (LAPs) of ophiacanthid brittle stars in external (a) and internal (b) views. 1-2. Ophiotreta sp. nov. innom 2 from the Langhian (middle Miocene) of Stotzing (1) and Mannersdorf (2), Austria. 1. NHMW 2012/0139/0003, proximal LAP. 2. NHMW 2012/0139/0001, proximal LAP. 3-4. Europacantha paciphila gen. et sp. nov. from the late Anisian (Middle Triassic) of Felsöörs, Hungary. 3. MHI 2090/1 (holotype), proximal to median LAP. 4. MHI 2091/1 (paratype), proximal LAP. 5-7. Ophiacantha jaegeri sp. nov. from the latest Hauterivian (Early Cretaceous) of Sarstedt, Germany. 5. GZG.INV.78595 (holotype), proximal LAP. 6. GZG.INV.78596 (paratype), median LAP. 7. GZG. INV.78597 (paratype), distal LAP. 8-9. Ophiacantha sp. nov. innom 1 from the latest Aptian to earliest Albian (Early Cretaceous) of Blake Nose, NE Atlantic. 8. GZG.INV.78599, proximal LAP. 9. GZG. INV.78600, distal LAP. 10. Ophiacantha sp. nov. innom 2 from the latest Aptian to earliest Albian (Early Cretaceous) of Blake Nose, NE Atlantic; GZG.INV.78601, distal LAP. One common scale bar per species.