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Diverse Late Jurassic Anomuran Assemblages from the Swabian Alb and Evolutionary History of Paguroids Based on Carapace Morphology

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Diverse Late Jurassic Anomuran Assemblages from the Swabian Alb and Evolutionary History of Paguroids Based on Carapace Morphology 132 R.H.B. Fraaije et al. Pilgrimcheles vonmeyeri n. sp. Material: Holotype (MAB k.3253), a near-complete shield Fig. 7A-C (total length 1.5 mm, max. width 1.5 mm). Etymology: Named in honour of christian erich her- Locality and horizon: Small local quarry at the Wester- Mann von Meyer (1801-1869), a well-known German pa- berg, with well-bedded sponge-microbial limestones and laeontologist. marls of the Aulacostephanus pseudomutabilis Zone of late Kimmeridgian (= ‘Malm delta 3-4’) age. Material: Holotype MAB k.3235, a near-complete shield with a maximum length and width of 4.0 mm and 4.0 mm, Diagnosis: Shield well calcified, of near-equal length and respectively; paratypes MAB k.3334 and MAB k.3335 with width, well areolated, with distinct regions, including an- a maximum length and width of 4.5, 5.0 mm and 4.5, 5.0 gular massetic region. Small triangular rostrum and about mm, respectively. similarly sized post-ocular spines. Post-antennal projections less distinct. Anterior portion of gastric region delimited by Locality and horizon: Small local quarry at the Wester- post-rostral ridge with central gastric groove. Long central berg, with well-bedded sponge-microbial limestones and gastric groove fading into median gastric rim posteriorly. marls of the Aulacostephanus pseudomutabilis Zone of late Typically reniform keraial regions. Kimmeridgian (= ‘Malm delta 3-4’) age. Description: Well-calcified and clearly areolated shield, of Diagnosis: Shield well calcified, length slightly exceeding about equal length and width, convex transversely, slightly width, well areolated, with many distinct regions, including convex longitudinally. Small short triangular rostrum and a massetic region. Rimmed, broad-based, triangular ros- about equally sized post-ocular spines. Post-antennal pro- trum and smaller triangular, post-ocular projections. Post- jections less distinct. Ocular-frontal area equalling about 57 antennal projections less distinct and not rimmed. Anterior per cent of total maximum width. Gastric region, bounded portion of gastric region delimited by post-rostral ridge posteriorly by cervical groove; anterior part delimited by with central gastric groove. Large globose massetic region post-rostral ridge. Post-rostral ridge centrally indented by bordered posterocentrally by smaller, yet distinct globose relatively long gastric groove fading posteriorly into central submassetic region. Typically reniform keraial regions. No rim, anteriorly a broad frontal ridge extending to rostrum. posterior parts of the carapace preserved. Prominent, angular and elongated massetic region about 140 per cent of length of narrow anterior branchial area. Description: Well-calcified and clearly areolated shield, Cervical groove anteriorly curving around reniform keraial length slightly exceeding width, convex transversely, slight- region and laterally incising lateral margin below anterior ly convex longitudinally. Rimmed, broad-based, triangular branchial area. Anterior of keraial region and bordering an- rostrum and post-ocular projections. Post-antennal pro- terior massetic region distinct oval submassetic region. No jections less distinct and not rimmed. Ocular-frontal area posterior parts of carapace preserved. equaling about 55 per cent of total maximum width. Pos- teriorly pointed, bluntly arrowhead-shaped gastric region, Remarks: Pilgrimcheles vonmeyeri n. sp. and P. kersteni bounded posteriorly by deep cervical groove; anterior part n. sp. can be distinguished from the type species of the ge- delimited by slightly undulose, post-rostral ridge and when nus, P. karolinae, in having a longer central gastric groove, cuticule is absent, covered by transverse crenulations. Post- smaller massetic region, longer anterior branchial area and rostral ridge centrally indented by relatively long gastric a central gastric rim. Pilgrimcheles vonmeyeri n. sp. is eas- groove fading posteriorly into faint central rim. Prominent, ily differentiated from the coeval P. kersteni n. sp. in having globose and elongated massetic region about 160 % length a less angular massetic region, a more convex postrostral of elongated anterior branchial area. Posterior part of cervi- ridge, a more distinctly rimmed frontal margin and a dis- cal groove pronounced and very deep, anteriorly curving tinct oval submassetic region. around reniform keraial region and laterally incising lateral margin below anterior branchial area. Anterior of keraial region a distinct oval submassetic region, bordering mas- Family Parapylochelidae Fraaije, kloMpMaker & setic region. Except for some very small parts posterior of artal anterior branchial area, no other posterior parts of carapace , 2012 preserved. Genus Housacheles Fraaije, van Bakel, jagt & sku- pien, 2013 Pilgrimcheles kersteni n. sp. Type species: Housacheles timidus raaije an akel Fig. 7D F , v B , jagt & skupien, 2013, by original designation. Etymology: Named in honour of geon kersten, a Dutch amateur palaeontologist and friend, who helped during sev- eral field trips and donated some of the material studied Housacheles ovalis n. sp. herein. Fig. 7F .
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