Valamunida haeggi Klompmaker and Robins, 2019

Hryniewicz, Krzysztof, Amano, Kazutaka, Bitner, Maria Aleksandra, Hagström, Jonas, Kiel, Steffen, Klompmaker, Adiël A., Mörs, Thomas, Robins, Cristina M. & Kaim, Andrzej, 2019, A late Paleocene fauna from shallow-water chemosynthesis-based ecosystems, Spitsbergen, Svalbard, Acta Palaeontologica Polonica 64 (1), pp. 101-141 : 127-130

Valamunida haeggi Klompmaker and Robins sp. nov.

Figs. 21, 22.

1925 Galathea sp. ; Hägg 1925: 48, pl. 6.28a.

1970 Galathea spitzbergica Gripp, 1927 ; Vonderbank 1970: 78, fig. 25 [not 25c]; pl. 6.2–6.7.

2013 Galathea spitzbergica Gripp, 1927 ; Robins 2013: 38, fig. 8.4.

ZooBank LSID: urn:lsid:zoobank.org:act:798CF3CB-27FE-406EBCFB-F26D76BBE2C9

Etymology: Named after Richard Hägg (1877–1957), who first figured specimens of this species.

Type material: Holotype: NRM-PZ Ar68001A, partial carapace (Fig. 21A). Paratypes: NRM-PZ Ar68001B ( Fig. 22C ), NRM-PZ Ar68010 ( Fig. 22B ), and NRM-PZ Ar68011 ( Fig. 22A ). All represent (partial) carapaces with cuticular layers variably preserved, all from the type locality and horizon.

Type locality: Zachariassendalen , Spitsbergen, Svalbard .

Type horizon: Cold seep carbonates from the Basilika Formation, upper Paleocene .

Material.—Additional material from the upper Paleocene, Zachariassendalen, Spitsbergen, Svalbard: NRM-PZ Ar 68001C, external mold partial branchial region; NRM-PZ Ar 68006, external mold left side carapace; NRM-PZ Ar68007, part of meso-metabranchial and partial cardiac region; NRM-PZ Ar68016, left mid-part of carapace. Additional material from the upper Paleocene, locality 500 m west of Trigonometric point 25, Hollendarbukta, Spitsbergen, Svalbard: GPIBo 86, left part carapace ( Vonderbank 1970: pl. 6.2); GPIBo 87, right part carapace ( Vonderbank 1970: pl. 6.3); GPIBo 88, central part gastric region ( Vonderbank 1970: pl. 6.4); GPIBo 89, central part gastric region ( Vonderbank 1970: pl. 6.5); GPIBo 90, left meso-metabranchial region ( Vonderbank 1970: pl. 6.6); GPIBo 91, anterior part gastric region and partial rostrum ( Vonderbank 1970: pl. 6.7).

Measurements.— Holotype, NRM-PZ Ar68001A: Lmax (without rostrum), 23.3 mm; Wmax, 18.4 mm. NRM-PZ Ar 68001B: L, not available; W, 18.0 mm. NRM-PZ Ar68010: L, not available; W, 8.8 mm. NRM-PZ Ar68011: L, 20.0 mm, W, 15.5 mm. GPIBo 88: L, not available; W (at gastric region), 10.2 mm. Dimensions of paratypes: GPIBo 86, NRM-PZ Ar68002, and additional material cannot be determined due to incomplete preservation.

Diagnosis.—Carapace longer than wide, rostrum trifid, spines on lateral margins of epibranchial anterior of meta-mesobranchial regions, grooves deeply incised. Mesogastric, protogastric, and epigastric divisions pronounced. Epigastric regions with strong spine surrounded by tubercles, anterior ones in row. Hepatic and epibranchial regions slightly inflated, ornamented with tubercles. Cardiac region elevated above remainder of carapace. Intestinal area smooth to less ornamented, deeply depressed near posterior margin.

Description.—Carapace subrectangular (L/W [without rostrum] 1.2–1.3), widens slightly posteriorly. Rostrum trifid, with narrow triangular central spine subsquare in cross-section, and two accessory spines; length and termination unknown. Orbits not exposed. Outer orbital margins bear base

Fig. 21. Munidid crustacean Valamunida haeggi Klompmaker and Robins gen. et sp. nov. from the upper Paleocene , Basilika Formation, Zachariassendalen A) and locality 500 m west from Trigonometric point 25, Hollendarbukta (B, C), Spitsbergen, Svalbard. A. Holotype, NRM-PZ Ar68001a, carapace in →

dorsal (A 1) and right lateral (A 2) views, frontal view (note base of outer orbital spine on left) (A 3), oblique view on anterior gastric region (arrow indicates upward spine on epigastric region) (A 4), external mold (A 5), rostral view (arrows indicate incomplete accessory spines of rostrum) (A 6). B. GPIBo 88, carapace in dorsal view (note bases of spines on epigastric regions) (B 1), right lateral view (note spines on lateral margin and at outer orbital angle) (B 2). C. GPIBo 86, carapace in dorsal view. B, C coated with ammonium chloride.

of large spine; lateral margins spined at epibranchial (3 bases of spines) and anterior of meta-mesobranchial regions (at least 1 base of spine). Grooves deeply incised; cervical and postcervical groove wide. Gastric region elevated slightly above frontal margin, well-defined, with pronounced mesogastric, protogastric, and epigastric divisions. Epigastric regions with two strong spines surrounded by randomly oriented tubercles posteriorly and laterally, small tubercles form oblique rows anterior to spines ( Fig. 22D 2 ). Protogastric areas with transverse ridges, may bear few spines/tubercles. Hepatic and epibranchial regions slightly inflated, ornamented with tubercles. Mesogastric region triangular with transverse ridges, mesogastric process may bear tubercles. Meta-/urogastric region wider than long, not delimited laterally, with interrupted transverse ridges. Cardiac region elevated above remainder of carapace, wider than long, with transverse ridges; anterior margin with straight strong groove, rest delimited by concave forward groove that may be straight posteriorly. Meso-metabranchial region confluent, with transverse ridges that can be interrupted in large specimens. Intestinal area smooth to weakly ornamented, deeply depressed near posterior margin. Posterior margin rimmed, concave, with ridges anterior to it. Cuticle variably present. Articulated appendages, venter, and abdomen not known.

Remarks.—It is possible that Gripp (1927) also studied some specimens conspecific with this species, as he studied four specimens, one of which is Protomunida spitzbergica (see above). The great majority of galatheoid carapaces from the upper Paleocene of Spitsbergen we have seen can be ascribed to the new species.

The marked depression at the anterior part of the intestinal region cannot be explained by post-mortem processes because we have observed this depression in four specimens across a size range. Ontogenetic variation is evident: (i) the largest specimen (holotype) shows more interrupted ridges at the meso-metabranchial regions than smaller specimens, (ii) smaller specimens appear more vaulted transversely, and (iii) the cardiac region appears more swollen in the largest specimen (= holotype). Intraspecific variation is also observed: some of the specimens bear tubercles laterally to the base of the mesogastric process and the there is some variation in the precise course and strength of transverse ridges, not attributable to ontogeny.

As mentioned for the previous species, the presence of cuticle does not seem to affect the presence and strength of ornamentation much for galatheoids. The cuticle is variably present on multiple specimens of the new species and provides an opportunity to evaluate its effect on appearance for this taxon. Upon examination of the specimens, the presence of cuticle indeed does not seem to affect the strength of the ornamentation for each of the figured specimens. The cuticle in the groove branching off the cervical groove of NRM-PZ Ar68010 appears, however, somewhat thicker in the deepest part of the groove ( Fig. 22B 4 ). The groove is still present with cuticle preserved, but may be somewhat shallower with cuticle, as previously shown for a raninoid crab ( Schweitzer et al. 2009: fig. 8).

Stratigraphic and geographic range. —Upper Paleocene cold seep carbonates from the Basilika Formation, Zachariassendalen and locality 500 m west of Trigonometric point 25, Hollendarbukta, and Fossildalen, Spitsbergen, Svalbard.

Figures

Fig. 22. Munidid crustacean Valamunida haeggi Klompmaker and Robins gen. et sp. nov. from the Paleocene Basilika Formation, Zachariassendalen, Spitsbergen, Svalbard. A. Paratype, NRM-PZAr68011, carapace in dorsal view (A1), left lateral view (note bases of lateral spines) (A2), frontal view with cross-section of base central rostral spine (A3). B. Paratype, NRM-PZ Ar68010, carapace in right lateral (B1) and dorsal (B2) views, oblique frontal view (note base of spine on right orbital angle) (B3), view of cross-sectioned cuticle in groove branching off cervical groove on left side (image width ~0.7 mm) (B4). C. Paratype, NRM-PZ Ar68001b, carapace in dorsal view. D. NRM-PZ Ar68002, two epigastric spines in oblique frontal view (D1), dorsal view of gastric region (D2).

Fig. 2. Transverse serial sections of the sellithyrid brachiopod Neoliothyrina nakremi Bitner sp. nov. paratype (ZPAL V.48/9-4) from the upper Paleocene, Basilika Formation, Fossildalen, Spitsbergen, Svalbard. L>20.2 mm. Numbers indicate distance in mm from the tip of the ventral umbo.

Fig.4.Aporrhaid and scaphandrid gastropods from the upper Paleocene, Basilika Formation, locality 500 m west from Trigonometric point 25, Hollendarbukta (A, B, D) and Fossildalen (C), Spitsbergen, Svalbard. A, B. Aporrhais cf. gracilis Koenen, 1885, GPIBo 117 (A) and GPIBo 116 (B) in lateral (A1, B1) and apical (A2, B2) views.C.?Aporrhais cf.gracilis Koenen, 1885, identified by Hägg (1925) as Nassa sp., NRM-PZ Mo 149182 in apical (C1), lateral C2) and latero-apertural (C3) views. D. Ellipsoscapha sp. GPIBo 115 in apertural (D1), lateral (D2), apical (D3), and abapical (D4) views.