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Paguristes timoni n. sp. (Fig. 2) Zoobank: urn:lsid:zoobank.org:act: C4F34FA0-7A19-46B4-91BC-C93C621CD977 Diagnosis. Keeled merus with row of small teeth on distal margin; moveable finger corneous; fixed finger covered with rows of alveolate tubercles, decreasing in size on distal end. Upper margin with tubercles; cutting edge with several teeth proximally. Walking legs with keeled edge and row of tubercles. Type material. The holotype, and sole specimen known to date, is CMM-I-4600. Etymology. Named after the legendary misanthrope and hermit, Timon of Athens, who was popularized in the play ‘Timon of Athens’ by William Shakespeare (1564–1616). Locality and stratigraphy. Driftwood Beach, Calvert County, Maryland, from the upper Miocene (Tortonian) Little Cove Point Member of the St. Marys Formation in a silty lens within Bed E (Ward & Andrews 2008). Kidwell et al. (2015) identified this level as belonging to “SM-C,” assigned to Shattuck zones 22–23 and part of dinocyst zone 8. Description. CMM-I-4600, preserved inside gastropod shell (Busycon sp.), length 25 mm, greatest width 17 mm. Manus missing from major (left) cheliped, carpus and merus preserved. Keeled merus with row of small teeth on distal margin. Minor (right) cheliped comprising complete propodus, lodged in gastropod aperture, measuring 7 mm length, 2 mm maximum width. Moveable finger corneous, fixed finger covered with rows of alveolate tubercles decreasing in size on distal end; most tubercles with alveoli, indicative of setal insertions; upper margin covered with tubercles; cutting edge with several teeth proximally; distal side not visible. Carapace fragment preserved but covered; small portion visible lacking any specific details; Single fragment of walking leg preserved showing keeled edge with row of tubercles. Several other fragments preserved, but unidentifiable due to weathering of specimen. Remarks. In this novel form, the left cheliped is larger than the right one, which is diagnostic feature of diogenid and annuntidiogenid hermit crabs (McLaughlin 2003; Fraaije 2014). The Maryland specimen is remarkably similar to the extant Paguristes candelae De Matos-Pita & Ramil, 2015, from Mauritania (see below). Discussion. Cheliped shape and ornament in P. timoni n. sp. compare closely with those of P. candelae, in that both have rows of tubercles and setae and tubercles decrease in size toward the distal end. The dorsomesial margin in P. candelae has three large tubercles; these are absent from P. timoni n. sp. The dorsal cheliped surface in the latter appears to be less convex in comparison with that of P. candelae, while the teeth along the cutting edge appear to be larger in the extinct form. The walking legs in both taxa show a keeled ridge with a row of spines, although the one in P. timoni n. sp. seems more acute.

Paguristes timoni n. sp. (Fig. 2) Zoobank: urn:lsid:zoobank.org:act: C4F34FA0-7A19-46B4-91BC-C93C621CD977 Diagnosis. Keeled merus with row of small teeth on distal margin; moveable finger corneous; fixed finger covered with rows of alveolate tubercles, decreasing in size on distal end. Upper margin with tubercles; cutting edge with several teeth proximally. Walking legs with keeled edge and row of tubercles. Type material. The holotype, and sole specimen known to date, is CMM-I-4600. Etymology. Named after the legendary misanthrope and hermit, Timon of Athens, who was popularized in the play ‘Timon of Athens’ by William Shakespeare (1564–1616). Locality and stratigraphy. Driftwood Beach, Calvert County, Maryland, from the upper Miocene (Tortonian) Little Cove Point Member of the St. Marys Formation in a silty lens within Bed E (Ward & Andrews 2008). Kidwell et al. (2015) identified this level as belonging to “SM-C,” assigned to Shattuck zones 22–23 and part of dinocyst zone 8. Description. CMM-I-4600, preserved inside gastropod shell (Busycon sp.), length 25 mm, greatest width 17 mm. Manus missing from major (left) cheliped, carpus and merus preserved. Keeled merus with row of small teeth on distal margin. Minor (right) cheliped comprising complete propodus, lodged in gastropod aperture, measuring 7 mm length, 2 mm maximum width. Moveable finger corneous, fixed finger covered with rows of alveolate tubercles decreasing in size on distal end; most tubercles with alveoli, indicative of setal insertions; upper margin covered with tubercles; cutting edge with several teeth proximally; distal side not visible. Carapace fragment preserved but covered; small portion visible lacking any specific details; Single fragment of walking leg preserved showing keeled edge with row of tubercles. Several other fragments preserved, but unidentifiable due to weathering of specimen. Remarks. In this novel form, the left cheliped is larger than the right one, which is diagnostic feature of diogenid and annuntidiogenid hermit crabs (McLaughlin 2003; Fraaije 2014). The Maryland specimen is remarkably similar to the extant Paguristes candelae De Matos-Pita & Ramil, 2015, from Mauritania (see below). Discussion. Cheliped shape and ornament in P. timoni n. sp. compare closely with those of P. candelae, in that both have rows of tubercles and setae and tubercles decrease in size toward the distal end. The dorsomesial margin in P. candelae has three large tubercles; these are absent from P. timoni n. sp. The dorsal cheliped surface in the latter appears to be less convex in comparison with that of P. candelae, while the teeth along the cutting edge appear to be larger in the extinct form. The walking legs in both taxa show a keeled ridge with a row of spines, although the one in P. timoni n. sp. seems more acute., Published as part of Wallaard, Jonathan J. W., Fraaije, René H. B., Van Bakel, Barry W. M., Nance, John R., Lindholm, Adam & Jagt, John W. M., 2023, New hermit crab species (Anomura, Paguroidea) from the upper Miocene St Marys Formation of Maryland (USA), preserved in their host shells, pp. 389-397 in Zootaxa 5227 (3) on pages 393-394, DOI: 10.11646/zootaxa.5227.3.7, http://zenodo.org/record/7518846, {"references":["Ward, L. W. & Andrews, G. W. (2008) Stratigraphy of the Calvert, Choptank, and St. Mary's formations (Miocene) in the Chesapeake Bay area, Maryland and Virginia. Virginia Museum of Natural History Memoir, 9, 1 - 60.","Kidwell, S. M., Powars, D. S., Edwards, L. E. & Vogt, P. R. (2015) Miocene stratigraphy and paleoenvironments of the Calvert Cliffs, Maryland. Bulletin of the Geological Society of America, 40, 231 - 279.","McLaughlin, P. A. (2003) Illustrated keys to families and genera of the superfamily Paguroidea (Crustacea: Decapoda: Anomura), with diagnoses of genera of Paguridae. Memoirsof Museum Victoria, 60 (1), 111 - 144.","Fraaije, R. H. B. (2014) Diverse Late Jurassic anomuran assemblages from the Swabian Alb and evolutionary history of paguroids based on carapace morphology. Neues Jahrbuch fur Geologie und Palaontologie Abhandlungen, 273 (2), 121 - 145.","De Matos-Pita, S. S. & Ramil, F. (2015) Hermit crabs (Decapoda: Crustacea) from deep Mauritanian waters (NW Africa) with the description of a new species. Zootaxa, 3926 (2), 151 - 190."]}

Genus Pagurus Fabricius, 1775 Type species. Cancer bernhardus Linnaeus, 1758, by monotypy. Species included. For data on extinct forms, reference is made to lists provided by Schweitzer et al. (2010) and to subsequent records by Beschin et al. (2012), De Angeli & Caporiondo (2017) and Polkowsky & Fraaije (2019). Extant species have recently been discussed by Lemaitre & McLaughlin (2021a)., Published as part of Wallaard, Jonathan J. W., Fraaije, René H. B., Van Bakel, Barry W. M., Nance, John R., Lindholm, Adam & Jagt, John W. M., 2023, New hermit crab species (Anomura, Paguroidea) from the upper Miocene St Marys Formation of Maryland (USA), preserved in their host shells, pp. 389-397 in Zootaxa 5227 (3) on page 390, DOI: 10.11646/zootaxa.5227.3.7, http://zenodo.org/record/7518846, {"references":["Fabricius, J. C. (1775) Systema entomologiae: sistens insectorum classes, ordines, genera, species, adiectis synonymis, locis, descriptionibus, observationibus. Officina Libraria Kortii, Flensbergi et Lipsiae, xxx + 832 pp.","Linnaeus, C. (1758) Systema naturae per regna tria naturae, secundumclasses, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Vol. 1. Editio 10. Reformata. Laurentius Salvius, Holmiae, 824 pp.","Schweitzer, C. E., Feldmann, R. M., Garassino, A., Karasawa, H. & Schweigert, G. (2010) Systematic list of fossil decapod crustacean species. Crustaceana Monographs, 10, 1 - 222.","Beschin, C., De Angeli, A., Checchi, A. & Zarantonello, G. (2012) Crostacei del giacimento eocenico di Grola presso Spagnago di Cornedo Vicentino (Vicenza, Italia settentrionale) (Decapoda, Stomatopoda, Isopoda). Museo di Archeologia e Scienze Naturali \" G. Zannato \", Montecchio Maggiore, Vicenza, 101 pp.","De Angeli, A. & Caporiondo, F. (2017) I granchi eremiti (Crustacea, Decapoda, Anomura, Paguroidea) dell'Eocene medio di cava \" Main \" di Arzignano (Vicenza, Italia settentrionale). Studi Trentini di Scienze Naturali, 96, 11 - 32. [http: // www. muse. it / it / Editoria-Muse / Studi-Trentini-Storia-Naturale / Documents / STSN _ 95 - 2016. aspx]","Polkowsky, S. & Fraaije, R. H. B. (2019) A new Oligocene hermit crab (Decapoda, Anomura, Paguroidea) from the erratic ' Sternberger Gestein', northern Germany. Neues Jahrbuch fur Geologie und Palaontologie Abhandlungen, 291 (1), 61 - 63. https: // doi. org / 10.1127 / njgpa / 2019 / 0789","Lemaitre, R. & McLaughlin, P. (2021 a) World Paguroidea & Lomisoidea database. Pagurus J. C. Fabricius, 1775. World Register of Marine Species. Available from: http: // www. marinespecies. org / aphia. php? p = taxdetails & id = 106854 (accessed 15 March 2021)"]}

Pagurus hazenorum n. sp. (Fig. 1) Zoobank: urn:lsid:zoobank.org:act: 9E06A12D-8371-4F45-B75F-60E3032C4847 Diagnosis. Major carpus (right) covered with small, randomly scattered tubercles, increasing in size toward outer margin, there becoming setose. On minor carpus (left), tubercles arranged in rows and slightly increasing in size toward distal end. Both claws densely covered with large granules, decreasing in size toward outer margin. Outer margins of propodus and dactylus covered with blunt teeth, smaller on dactylus. Outer lateral surface of dactylus with longitudinal, medially elevated surface. Walking legs covered with row of teeth, decreasing in size toward distal end. Dactylus of walking leg only covered by blunt teeth and surface with some longitudinal grooves. Type material. The holotype, and sole specimen known to date, is CMM-I-4785. It is preserved inside its gastropod host shell (Buccinofusus parilis Conrad, 1832), which is severely damaged and allows the hermit crab inside to be observed in more detail. The right and left chelipeds are preserved within the gastropod aperture. A relatively complete walking leg, consisting of carpus, propodus and dactylus, is seen posterior of that aperture. A second walking leg, of which only the carpus is preserved, is found anterior of the aperture, while several fragments of other legs are present just behind the chelipeds. The carapace should have been situated here, but this part of the individual has suffered considerable damage and there is no trace of a carapace. Etymology. In honor of Dr Robert M. Hazen, senior staff scientist at the Carnegie Institution for Science, and his wife, Margaret Hazen, writer and historian. Locality and stratigraphy. Driftwood Beach, Calvert County, Maryland, from the upper Miocene (Tortonian) Little Cove Point Member of the St. Marys Formation in a silty lens within Bed E (Ward & Andrews 2008). Kidwell et al. (2015) identified this level as belonging to “SM-C,” assigned to Shattuck zones 22–23 and part of dinocyst zone 8. Description. Chelipeds stout, broad, with propodus of major (right) claw measuring 21 mm by 14 mm; that of minor (left) claw measuring 16 mm by 12 mm. Entire surface of carpus of major claw covered with small, randomly scattered tubercles, increasing in size and setation toward outer margin. Carpus of minor claw with tubercles arranged in rows and slightly increasing in size toward distal end. Both left and right propodi densely covered with large granules, decreasing in size toward outer margin. Outer margin of propodus arcuate; that of dactylus almost straight. Outer margin of both propodus and dactylus covered with blunt teeth, smaller on latter. Outer lateral surface of dactylus covered with longitudinal, medially elevated ridge. Walking legs covered with row of teeth, decreasing in size toward distal end. Dactylus of walking leg with blunt teeth; surface with some longitudinal grooves. Remarks. The new species compares fairly well with the extant Pagurus impressus (Benedict, 1892), from the west coast of Florida (Provenzano 1959), as well as with Diacanthurus rubricatus Henderson, 1888, from the coast of New Zealand and P. bernhardus (Linnaeus, 1758) from the eastern North Atlantic. Discussion. The assignment of the Maryland material to the genus Pagurus is based on several morphological features which P. hazenorum n. sp. has in common with extant congeners, as described below. Although P. hazenorum n. sp. is preserved in situ within its gastropod shell, the carapace appears to be missing, most likely as a result of the damage to the host shell. Overall, the shape of the dactylus is more elongated and bears a closer cover of granules in P. impressus, whereas that of P. hazenorum n. sp. is stout, with blunt teeth along the outer edge and a cover of large granules. Chelipeds of the present-day D. rubricatus bear small spines, in equal density as in P. hazenorum n. sp. Pagurus bernhardus is comparable as well; this has a coarse ornament which, however, is less dense than that of P. hazenorum n. sp. (see Hyžný & Dulai 2021: fig. 35.8). Our comparison of P. hazenorum n. sp. with both extant and extinct species has yielded numerous forms with closely comparable anatomical features. Molecular and genetic research carried out recently on extant representatives of the genus Pagurus has shown that this is in fact a wastebasket taxon, comprising forms with closely comparable morphologies, but widely divergent genetic structures (e.g., Olguin & Mantelatto 2013; Sultana et al. 2018). Naturally, genetic research cannot be carried out on extinct forms, which makes any workable subdivisions of the genus Pagurus even more difficult. This morphological similarity amongst genetically diverse species is most likely a reflection of functional morphology. Particularly in paguroids, the shell has a marked impact on cheliped shape, and most hermit crabs inhabit comparable mollusks, which explains the closely comparable morphology of the chelipeds. In the fossil record, isolated paguroid chelipeds (mostly propodi) are quite common, whereas carapaces are extremely rare. In view of this, it is highly unlikely that the difficulties surrounding the ‘lump’ taxon Pagurus can be resolved on the basis of extinct forms., Published as part of Wallaard, Jonathan J. W., Fraaije, René H. B., Van Bakel, Barry W. M., Nance, John R., Lindholm, Adam & Jagt, John W. M., 2023, New hermit crab species (Anomura, Paguroidea) from the upper Miocene St Marys Formation of Maryland (USA), preserved in their host shells, pp. 389-397 in Zootaxa 5227 (3) on pages 391-392, DOI: 10.11646/zootaxa.5227.3.7, http://zenodo.org/record/7518846, {"references":["Conrad, T. A. (1832) Fossil shells of the Tertiary formations of North America, illustrated by figures drawn on stone by T. A. Conrad, 1 (2), 21 - 28. [reprinted by Harris, G. D., 1893 and by the Paleontological Research Institution, Ithaca, New York, 1963]","Ward, L. W. & Andrews, G. W. (2008) Stratigraphy of the Calvert, Choptank, and St. Mary's formations (Miocene) in the Chesapeake Bay area, Maryland and Virginia. Virginia Museum of Natural History Memoir, 9, 1 - 60.","Kidwell, S. M., Powars, D. S., Edwards, L. E. & Vogt, P. R. (2015) Miocene stratigraphy and paleoenvironments of the Calvert Cliffs, Maryland. Bulletin of the Geological Society of America, 40, 231 - 279.","Provenzano Jr., A. J. (1959) The shallow-water hermit crabs of Florida. Bulletin of Marine Science, 9 (4), 349 - 420.","Henderson, J. R. (1888) Report on the Anomura collected by H. M. S. \" Challenger \" during the years 1873 - 76. Scientific results of the exploratory voyage of HMS Challenger, Zoology, 27, i - xi + 1 - 221 pp., 21 pls.","Linnaeus, C. (1758) Systema naturae per regna tria naturae, secundumclasses, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Vol. 1. Editio 10. Reformata. Laurentius Salvius, Holmiae, 824 pp.","Hyzny, M. & Dulai, A. (2021) Badenian decapods of Hungary, GeoLitera Publishing House, Institute of Geosciences, University of Szeged, Szeged, 300 pp.","Olguin, N. & Mantelatto, F. L. (2013) Molecular analysis validates of some informal morphological groups of Pagurus (Fabricius, 1775) (Anomura: Paguridae) from South America. Zootaxa, 3666 (4), 436 - 448.","Sultana, Z., Asakura, A., Kinjo, S., Nozawa, M., Nakano, T. & Ikeo, K. (2018) Molecular phylogeny of ten intertidal hermit crabs of the genus Pagurus inferred from multiple mitochondrial genes, with special emphasis on the evolutionary relationship of Pagurus lanuginosus and Pagurus maculosus. Genetica, 146 (4), 369 - 381."]}

Genus Paguristes Dana, 1851 Type species. Pagurus weddellii H. Milne Edwards, 1848. Included species. For a listing of fossil taxa, reference is made to Schweitzer et al. (2010), Gagnaison (2012), Beschin et al. (2016, 2018), De Angeli & Caporiondo (2017), Karasawa & Fudouji (2018), Jakobsen et al. (2020), Marangon & De Angeli (2020) and Wallaard et al. (2020). For extant forms, reference is made to Lemaitre & McLaughlin (2021b)., Published as part of Wallaard, Jonathan J. W., Fraaije, René H. B., Van Bakel, Barry W. M., Nance, John R., Lindholm, Adam & Jagt, John W. M., 2023, New hermit crab species (Anomura, Paguroidea) from the upper Miocene St Marys Formation of Maryland (USA), preserved in their host shells, pp. 389-397 in Zootaxa 5227 (3) on page 392, DOI: 10.11646/zootaxa.5227.3.7, http://zenodo.org/record/7518846, {"references":["Dana, J. D. (1851) Conspectus crustaceorum quae in orbis terrarum circumnavigatione, Carolo Wilkes e classe reipublicae foederata educe, lexit et descripsit. Paguridea. Proceedings of the Academy of Natural Sciences of Philadelphia, 5, 267 - 272.","Milne Edwards, H. (1848) Note sur quelques nouvelles especes du genre Pagure. Annales des Sciences naturelles, Serie 3, Zoologie, 10, 59 - 64.","Schweitzer, C. E., Feldmann, R. M., Garassino, A., Karasawa, H. & Schweigert, G. (2010) Systematic list of fossil decapod crustacean species. Crustaceana Monographs, 10, 1 - 222.","Gagnaison, C. (2012) Des bernard-l'hermites dans les faluns miocenes de Channay-sur-Lathan (Indre-et-Loire, France). Cossmanniana, 14, 67 - 72.","Beschin, C., Busulini, A., Tessier, G. & Zorzin, R. (2016) I crostacei associati a coralli nell'Eocene inferiore dell'area di Bolca (Verona e Vicenza, Italia nordorientale). In: Memorie del Museo Civico di Storia naturale di Verona. Vol. 2. Sezione Scienze della Terra, 9, pp. 13 - 189.","Beschin, C., Busulini, A., Fornaciari, E., Papazzoni, C. A. & Tessier, G. (2018) La fauna di Crostacei associati a coralli dell'Eocene superiore di Campolongo di Val Liona (Monti Berici, Vicenza, Italia nordorientale). Bollettino del Museo di Storia naturale di Venezia, 69, 129 - 215.","De Angeli, A. & Caporiondo, F. (2017) I granchi eremiti (Crustacea, Decapoda, Anomura, Paguroidea) dell'Eocene medio di cava \" Main \" di Arzignano (Vicenza, Italia settentrionale). Studi Trentini di Scienze Naturali, 96, 11 - 32. [http: // www. muse. it / it / Editoria-Muse / Studi-Trentini-Storia-Naturale / Documents / STSN _ 95 - 2016. aspx]","Karasawa, H. & Fudouji, Y. (2018) Two new species of hermit crabs (Decapoda: Anomura) from the Paleogene Kishima Group, Saga Prefecture, Japan. Bulletin of the Mizunami Fossil Museum, 44, 23 - 28.","Jakobsen, S. L., Fraaije, R. H. B., Jagt, J. W. M. & Van Bakel, B. W. M. (2020) New early Paleocene (Danian) paguroids from deep-water coral / bryozoan mounds at Faxe, eastern Denmark. Geologija, 63, 47 - 56. https: // doi. org / 10.5474 / geologija. 2020.005","Marangon, S. & De Angeli, A. (2020) New hermit crabs (Crustacea, Anomura, Paguroidea) from the Lower Oligocene of the Ligure Piemontese Basin, northwest Italy. In: Jagt, J. W. M., Fraaije, R. H. B., Van Bakel, B. W. M., Donovan, S. K., Mellish, C. & Schweigert, G. (Eds.), A lifetime amongst fossil crustaceans: a tribute to Joseph S. H. Collins (1927 - 2019). Neues Jahrbuch fur Geologie und Palaontologie Abhandlungen, 286 (1 - 2), pp. 157 - 165. https: // doi. org / 10.1127 / njgpa / 2020 / 0895","Wallaard, J. J. W., Fraaije, R. H. B., Jagt, J. W. M., Klompmaker, A. A. & Van Bakel, B. W. M. (2020) The first record of a paguroid shield (Anomura, Annuntidiogenidae) from the Miocene of Cyprus. Geologija, 63 (1), 37 - 43. https: // doi. org / 10.5474 / geologija. 2020.004","Lemaitre, R. & McLaughlin, P. (2021 b) World Paguroidea & Lomisoidea database. Paguristes Dana, 1851. World Register of Marine Species. Available from: http: // www. marinespecies. org / aphia. php? p = taxdetails & id = 106844 (accessed 18 November 2021)"]}

Pagurus hazenorum n. sp. (Fig. 1) Zoobank: urn:lsid:zoobank.org:act: 9E06A12D-8371-4F45-B75F-60E3032C4847 Diagnosis. Major carpus (right) covered with small, randomly scattered tubercles, increasing in size toward outer margin, there becoming setose. On minor carpus (left), tubercles arranged in rows and slightly increasing in size toward distal end. Both claws densely covered with large granules, decreasing in size toward outer margin. Outer margins of propodus and dactylus covered with blunt teeth, smaller on dactylus. Outer lateral surface of dactylus with longitudinal, medially elevated surface. Walking legs covered with row of teeth, decreasing in size toward distal end. Dactylus of walking leg only covered by blunt teeth and surface with some longitudinal grooves. Type material. The holotype, and sole specimen known to date, is CMM-I-4785. It is preserved inside its gastropod host shell (Buccinofusus parilis Conrad, 1832), which is severely damaged and allows the hermit crab inside to be observed in more detail. The right and left chelipeds are preserved within the gastropod aperture. A relatively complete walking leg, consisting of carpus, propodus and dactylus, is seen posterior of that aperture. A second walking leg, of which only the carpus is preserved, is found anterior of the aperture, while several fragments of other legs are present just behind the chelipeds. The carapace should have been situated here, but this part of the individual has suffered considerable damage and there is no trace of a carapace. Etymology. In honor of Dr Robert M. Hazen, senior staff scientist at the Carnegie Institution for Science, and his wife, Margaret Hazen, writer and historian. Locality and stratigraphy. Driftwood Beach, Calvert County, Maryland, from the upper Miocene (Tortonian) Little Cove Point Member of the St. Marys Formation in a silty lens within Bed E (Ward & Andrews 2008). Kidwell et al. (2015) identified this level as belonging to “SM-C,” assigned to Shattuck zones 22–23 and part of dinocyst zone 8. Description. Chelipeds stout, broad, with propodus of major (right) claw measuring 21 mm by 14 mm; that of minor (left) claw measuring 16 mm by 12 mm. Entire surface of carpus of major claw covered with small, randomly scattered tubercles, increasing in size and setation toward outer margin. Carpus of minor claw with tubercles arranged in rows and slightly increasing in size toward distal end. Both left and right propodi densely covered with large granules, decreasing in size toward outer margin. Outer margin of propodus arcuate; that of dactylus almost straight. Outer margin of both propodus and dactylus covered with blunt teeth, smaller on latter. Outer lateral surface of dactylus covered with longitudinal, medially elevated ridge. Walking legs covered with row of teeth, decreasing in size toward distal end. Dactylus of walking leg with blunt teeth; surface with some longitudinal grooves. Remarks. The new species compares fairly well with the extant Pagurus impressus (Benedict, 1892), from the west coast of Florida (Provenzano 1959), as well as with Diacanthurus rubricatus Henderson, 1888, from the coast of New Zealand and P. bernhardus (Linnaeus, 1758) from the eastern North Atlantic. Discussion. The assignment of the Maryland material to the genus Pagurus is based on several morphological features which P. hazenorum n. sp. has in common with extant congeners, as described below. Although P. hazenorum n. sp. is preserved in situ within its gastropod shell, the carapace appears to be missing, most likely as a result of the damage to the host shell. Overall, the shape of the dactylus is more elongated and bears a closer cover of granules in P. impressus, whereas that of P. hazenorum n. sp. is stout, with blunt teeth along the outer edge and a cover of large granules. Chelipeds of the present-day D. rubricatus bear small spines, in equal density as in P. hazenorum n. sp. Pagurus bernhardus is comparable as well; this has a coarse ornament which, however, is less dense than that of P. hazenorum n. sp. (see Hyžný & Dulai 2021: fig. 35.8). Our comparison of P. hazenorum n. sp. with both extant and extinct species has yielded numerous forms with closely comparable anatomical features. Molecular and genetic research carried out recently on extant representatives of the genus Pagurus has shown that this is in fact a wastebasket taxon, comprising forms with closely comparable morphologies, but widely divergent genetic structures (e.g., Olguin & Mantelatto 2013; Sultana et al. 2018). Naturally, genetic research cannot be carried out on extinct forms, which makes any workable subdivisions of the genus Pagurus even more difficult. This morphological similarity amongst genetically diverse species is most likely a reflection of functional morphology. Particularly in paguroids, the shell has a marked impact on cheliped shape, and most hermit crabs inhabit comparable mollusks, which explains the closely comparable morphology of the chelipeds. In the fossil record, isolated paguroid chelipeds (mostly propodi) are quite common, whereas carapaces are extremely rare. In view of this, it is highly unlikely that the difficulties surrounding the ‘lump’ taxon Pagurus can be resolved on the basis of extinct forms.