A new species of clawed lobster, Hoploparia albertaensis, is reported from the late Coniacian, shallow-marine Bad Heart Formation of northwestern Alberta, Canada. Hoploparia is a well-known, clawed lobster genus with a record extending from Early Cretaceous (Valanginian) to Miocene. Fifty-one species of Hoploparia are known worldwide; 13 from the North American Western Interior Seaway. None of the 12 other Interior Seaway species, of any age, closely resembles the new species. The new species strongly resembles Hoploparia gabbi Pilsbry, 1901 from the upper Santonian–lower Campanian of the U.S. Mid-Atlantic Coastal Plain.

Ammonoid faunas of late Kinderhookian (Early Mississippian) age, virtually unknown previously in the American West, are described from several localities in New Mexico, Nevada, Utah, Idaho, and Montana. This study is based upon approximately 130 specimens from 33 collections. These specimens are variously assigned to at least 15 species in the following taxa: Protocanites, Imitoceras, Gattendorfia (Gattendorfia), Kazakhstania, Pericyclus (Goniocyclus), Rotopericyclus (Rotopericyclus), and R. (Hammatocyclus). The genus Muensteroceras, once widely regarded as appearing in the Kinderhookian, is unrepresented in these collections.

The western faunas are characterized by the predominance of the pericyclids and relative scarcity of Imitoceras. Midcontinent faunas of the same age are characterized by the predominance of Imitoceras, scarcity of Pericyclus (Goniocyclus), and presence of Prodromites. Ammonoid faunas of early Osagean age differ in the presence of abundant Muensteroceras and rare Pericyclus (Pericyclus) and in the absence of Prodromites and Pericyclus (Goniocyclus).

Most of the late Kinderhookian ammonoids, both in the West and in the Midcontinent, are assignable to the Siphonodella isosticha–Upper S. crenulata Conodont Zone of Sandberg et al. (1978). A few are referable to the Lower Siphonodella crenulata Zone of the same authors. No ammonoids have been described from equivalent beds in Europe which are included in the Siphonodella crenulata Zone of Voges (1960), despite the fact that Voges regarded this conodont zone as equivalent to the ammonoid Zone CuIIa of Schmidt (1925, p. 493). Based upon conodont correlations, the American Pericyclus (Goniocyclus) fauna is middle Tournaisian (Tn2b, c) in age and, with its Midcontinent equivalents, represents a part of the section between the Gattendorfia and the Pericyclus zones of Europe, from which ammonoids are as yet undescribed.

One new subgenus is described in this paper: Pericyclus (Goniocyclus), its type species Goniatites blairi Miller and Gurley, 1896. New species described include Pericyclus (Goniocyclus) cooperi, P. (G.) costulatus, P. (G.) antelopensis, P. (G.) rockymontanus, P. (G.) filaris, P. (G.)? decipiens, Rotopericyclus (Rotopericyclus) pinyonensis, and R. (Hammatocyclus) brazerensis.

The kutorginates are commonly the most abundant rhynchonelliform brachiopod found in the early Cambrian; they are also some of the oldest known rhynchonelliforms, first appearing in the Unnamed Series 2 (Atdabanian equivalent) and becoming extinct sometime in Cambrian Series 3 (Amgaian equivalent). Moreover, kutorginates are the first known member of the rhynchonelliforms for which we have a detailed knowledge of their soft-part anatomy, including the lophophore, digestive tract, and pedicle—all exceptionally preserved in Kutorgina chengjiangensis Zhang et al., 2007 from the early Cambrian Chengjiang Lagerstätte of southern China. The stout and annulated pedicle in the original report was described as protruding between the valves; however, newly collected better-preserved material now clearly shows that the pedicle actually protrudes from the apical perforation of Kutorgina chengjiangensis. This type of apical pedicle has also been described from other early Cambrian rhynchonelliforms, including the problematic chileate Longtancunella chengjiangensis (Zhang et al., 2011a). Exceptionally preserved similar pedicles are also known to emerge apically from the Silurian chileate dictyonellid Eichwaldia subtrigonalis Billings, 1858, as well as from the recently described Silurian chileate Trifissura rigida Holmer, Popov, and Bassett, 2014. However, it is clear that the only other exceptionally preserved kutorginate—a silicified Nisusia—was provided with an adult pedicle emerging between the valves from a posterior gap; thus, Nisusia has two pedicle openings. However, the apical foramen may represent the earliest attachment of the larvae, which subsequently became nonfunctional through ontogeny. It is suggested that both types of attachment strategies may have appeared early in the stem lineage of the Rhynchonelliformea.

Herbivory is a common ecological function among extant lepidosaurs, but little is known about the origin of this feeding strategy within Lepidosauria. Here we describe a sphenodontian (Lepidosauria) from the Late Triassic of western North America, Trullidens purgatorii n. gen. n. sp., that reveals new aspects of the earliest radiation of herbivorous lepidosaurs. This taxon is represented by an isolated lower jaw with robust structure bearing transversely widened dentition and extensive wear facets, suggesting a masticatory apparatus specialized for herbivory. An unusual ‘incisor-like’ tooth is present at the anterior end of the jaw; a unique feature among lepidosaurs, this tooth is convergent with the incisors of extant rodents and lagomorphs. Phylogenetic analyses support the placement of this taxon within opisthodontian sphenodontians, a group sharing derived cranio-dental morphologies specialized for herbivory. The new taxon was recovered in a recently discovered and unnamed series of Upper Triassic strata in southeastern Colorado, USA, exposed in Canyons incised by the Purgatoire River and its tributaries. These strata comprise a dominantly red-bed sequence of conglomerates, sandstones, and siltstones deposited in a fluvio-lacustrine setting, preserving a Late Triassic biota of invertebrate and vertebrate ichnofossils, plant macrofossils, bony fish, temnospondyl amphibians, and reptiles. We use aetosaur osteoderms as biostratigraphic links to the nearby Chinle Formation of Arizona, USA, establishing a middle Norian age for these strata. The presence of an opisthodontian from western equatorial Pangaea in the Norian Stage reveals a near-global radiation of this clade across the Pangaean supercontinent during the Late Triassic.

UUID: http://zoobank.org/A737c03f-863a-488e-a860-5cc914548774.

Some rare microscopic cycloneuralians are present in the Cambrian of South China, represented by Eopriapulites and Eokinorhynchus (both early Cambrian), fossil embryos of Markuelia (middle to late Cambrian), and palaeoscolecids (early to late Cambrian). Among them, palaeoscolecids are relatively diverse and abundant. Here, we describe new material of three-dimensionally phosphatized and microscopic cycloneuralians from the Paibian Stage of Wangcun Lagerstätte, western Hunan, South China. New material includes fossil embryos assignable to Markuelia sp., two other types of fossil embryos, and three species of palaeoscolecids, including Dispinoscolex decorus Duan, Dong, and Donoghue, 2012, Schistoscolex hunanensis Duan, Dong, and Donoghue, 2012, and Austroscolex sinensis new species. The palaeoscolecid fragments differ mainly in size and armor of the trunk annuli. Since Eokinorhynchus and Eopriapulites occurred the earliest among the Cambrian cycloneuralians, it is proposed here that: (1) cycloneuralians originated in the Cambrian Fortunian small shelly faunas rather than in the early Cambrian macrobenthos, (2) ancestral cycloneuralians may have simple trunk armor, and (3) Eopriapulites represents an ancestral cycloneuralian.

A new enantiornithine, Musivavis amabilis n. gen. n. sp., is reported from the Lower Cretaceous Jehol Biota in western Liaoning, China. The new taxon is similar to the bohaiornithids in the robust subconical teeth, bluntly expanded omal ends of the furcula, caudolaterally oriented lateral trabeculae with triangular distal ends of the sternum, and a robust second pedal digit. Yet it differs from members of Bohaiornithidae in several features recalling other enantiornithine lineages, such as the acuminate rostral ramus of maxilla, the shape of the coracoid lateral margin, the presence of craniolateral processes on the sternum, the proportions of the manual phalanges, and the unspecialized third pedal ungual phalanx. A comprehensive phylogenetic analysis of Mesozoic birds shows that homoplasy significantly affects the reconstruction of enantiornithine relationships. When all phylogenetic characters are considered of equal weight, Musivavis is reconstructed in a lineage related to a radiation of large-bodied enantiornithines including Bohaiornithidae and Pengornithidae. Alternative scenarios based on progressive downweighting of the homoplastic characters support more basal placements of the pengornithids among Enantiornithes, but do not alter the affinity of Musivavis as a member of the “bohaiornithid-grade” group.

UUID: http://zoobank.org/617c7062-21ab-4d33-ae80-4edf5a129683

A new genus, Calorebama, is proposed for a clade of pseudolivine gastropods (family Buccinidae) that has its earliest species in the lower Paleocene (Danian) of Alabama, its next earliest species in the upper Paleocene (Thanetian) of Alabama, and its subsequent species in the Eocene of California, Oregon, and Washington. Calorebama is characterized by an inflated biconical shape, a biangulate body whorl usually with strong nodes on the shoulder, and fine to medium spiral ribbing that is coarser anterior to the medial pseudolivine groove.

Previously, these pseudolivines now being placed in Calorebama were assigned to the genus Pseudoliva. Study of the literature and every available museum specimen showed Calorebama to have five species and two subspecies, all of which have biostratigraphic integrity.

Calorebama unicarinata (Aldrich) is the earliest species, and it, along with C. tuberculifera (Conrad), are the only known Gulf Coast species. Calorebama dilleri dilleri (Dickerson) is the earliest representative of the genus on the West Coast of North America, and it arrived during the early Eocene (Ypresian). Probable geographic isolation of C. dilleri dilleri in central and southern California resulted in lineage splitting and the appearance of C. dilleri lineata (Gabb), which phyletically evolved into C. inornata (Dickerson). Calorebama dilleri dilleri persisted in northern California and phyletically evolved into C. dilleri kirbyi (Clark), which similarly evolved into C. volutaeformis (Gabb).

Calorebama inornata and C. volutaeformis, the youngest species of the genus, became widely distributed along the West Coast of North America before becoming extinct by the end of the earliest late Eocene.

Linuparus (Linuparus) korura n. sp. is described from Bortonian (middle Eocene) rocks in Otaio Gorge, South Canterbury, New Zealand. This discovery represents the first occurrence of the genus in New Zealand and the first notice of a fossil occurrence of the subgenus which is represented by three modern Indo-Pacific species. Comparison of key morphological descriptors suggests that L. korura is related to L. scyllariformis and L. trigonis. A stridulatory mechanism, similar to that seen on modern Linuparus, is described for the first time from the fossil record.

The Cretaceous and early Cenozoic species of the shallow-marine, warm-water bivalve Plicatula from California (United States) and Baja California (Mexico) are reviewed, and three new species are named. All of these species are representatives of Plicatula and not of the closely related taxon Harpax, which is associated with high-latitude and cool-water regions. The earliestknown Cretaceous species of Plicatula from the study area is P. variata Gabb, 1864, from Lower Cretaceous (Hauterivian Stage) strata in northern California, and our studies show it to be conspecific with Plicatula onoensis Anderson, 1958.

Plicatula allisoni new species is from Lower Cretaceous (Albian Stage) strata in Baja California, Mexico. Plicatula modjeskaensis new species is from Upper Cretaceous (Turonian Stage) strata in the Santa Ana Mountains, southern California. A possible new species from the same strata is also mentioned. A poorly preserved specimen of Plicatula? sp. is known from Upper Cretaceous (upper Campanian to lower Maastrichtian) strata in northern California.

The only Paleocene species of Plicatula from the study area is P. ostreiformis Stanton, 1896, from lower Paleocene strata of Lake County, northern California, and our studies show it to be conspecific with Ostrea buwaldana Dickerson, 1914. The only previously described Eocene species of Plicatula from the study area is P. juncalensis Squires, 1987, from lower middle Eocene (“Capay Stage”) strata of Los Angeles County, southern California. Plicatula surensis new species is from middle lower Eocene (“Capay Stage”) strata in Baja California Sur, Mexico. In addition, there is a Plicatula? sp. from Eocene strata of Baja California Sur, Mexico.

Although Plicatula is of uncommon occurrence north of Baja California, its thermophilic trait makes it useful in recognizing periods of warm climate.

A preliminary survey of benthic invertebrates off central west Florida provides documentation of modern epifaunal communities on a low-gradient carbonate slope. Three large-scale biofacies occur in soft-sediment carbonate environments between 200 and 2,000 m: an Echinoderm biofacies (200–550 m) dominated by a diverse assemblage of echinoderms, gastropods, and decapod crustaceans; a Penaeid shrimp–conical mound biofacies (550–1,200 m) characterized by large bioturbation structures; and a Microbial mat biofacies (1,200–2,000 m) with only rare epifaunal invertebrates. A fourth, hard-substrate biofacies reflects the presence of localized Miocene and Pleistocene hardgrounds in water depths of 200–600 m. This illustrates that hard-substrate biofacies may be laterally correlative with soft-sediment biofacies in a slope setting, thus producing a mosaic of contrasting faunal associations. All four biofacies have low population densities, presumably as a consequence of relatively low surface productivity. All four biofacies also show biogeographic affinity with other faunas at intermediate depths in the Caribbean region. Depth-related faunal transitions on the west Florida slope correlate with substrate and current velocity. Decreasing species diversity and abundance and a biofacies transition from suspension-feeding to deposit-feeding assemblages correlate with increasing depth, a decrease in mean grain size, and an increase in organic content of the sediment. This biofacies model may provide a modern analogue for faunas of ancient low-gradient slopes such as those of Cretaceous “shelf-sea” chalks of northwestern Europe.

A well-preserved omission surface (sedimentary discontinuity) in an outcrop near Alcoi in southeastern Spain displays trace fossils and body fossils that reflect a dynamic benthic community during the Miocene (Langhian–Tortonian). This outcrop, besides being the type locality of Spongeliomorpha iberica Saporta, 1887, exhibits other abundant trace fossils, such as Glossifungites saxicava Łomnicki, 1886 and Gastrochaenolites ornatus Kelly and Bromley, 1984. These trace fossils are restricted to a single stratigraphic horizon and constitute a typical firmground ichnoassemblage of the Glossifungites ichnofacies. The interiors of some of the Glossifungites and Spongeliomorpha burrows were occupied by encrusting balanomorph barnacles (Actinobalanus dolosus Darwin, 1854). This paper is the first report of cryptic barnacles colonizing the interior of open burrows that constitute a typical firmground ichnocoenose in the fossil record. Detailed ichnologic study demonstrates that the ichnospecies Glossifungites saxicava stands as a valid ichnotaxon and is not a synonym of the ichnogenus Rhizocorallium, as has been suggested by some previous workers.

Peligrochelys walshae is a meiolaniform turtle originally described based on four specimens represented by cranial remains found in the classic locality of Punta Peligro (Chubut, Argentina) in outcrops of the Salamanca Formation (Danian). Recent field work in the vicinity of Punta Peligro resulted in the discovery of almost 30 new specimens, represented by cranial and postcranial remains that can be assigned to P. walshae. In this contribution, we provide a detailed anatomical description of the new specimens, provide an emended diagnosis for the species, and explore its phylogenetic relationships based on all anatomical data available for the species. The new specimens bring valuable information about the anatomy of the skull and postcranium of P. walshae as well as for meiolaniforms in general. The 3D preservation of the skull bones allows us to provide a 3D reconstruction using novel techniques. The updated phylogenetic analysis confirms that P. walshae is part of the clade Meiolaniformes, which spans from the Early Cretaceous until the Holocene and contains the giant, horned turtles (Meiolaniidae). This phylogenetic analysis reinforces the previous hypothesis that the clade Meiolaniformes is dominated by Gondwanan taxa, but also includes some Laurasian representatives. Alternate phylogenetic positions of taxa included in Meiolaniformes in this analysis were tested using the Templeton test. The lineage leading to Peligrochelys walshae is the only meiolaniform non-meiolaniid lineage to have survived the K-Pg mass extinction; its study provides valuable information to evaluate the effects of the K-Pg extinction in turtles.

Many ichnological taxa named by Edward Hitchcock have never been adequately described and illustrated. Among these is the ichnogenus Antipus Hitchcock (1858, p. 115) with two species: A. flexiloquus based on specimens AC (=Amherst College, Amherst, Massachusetts) 35/25 and AC 41/52 (designated the type specimen by Lull 1904, p. 536); and A. bifidus based on specimens AC 23/3, AC 17/2, and AC 23/2 (designated the type specimen by Hitchcock 1865, p. 56). Lull (1904, p. 536) regarded A. bifidus as “… extremely doubtful…” and did not consider it in later publications (e.g., Lull 1915, 1953). The impressions ascribed to A. bifidus might be organic in origin, but if they are trackways, they are totally unlike the tracks of A. flexiloquus. Antipus bifidus is here regarded a nomen dubium because it is undiagnostic. Referred specimen AC 35/25, a small, thin slab of micaceous shale (approximately 87 mm by 96 mm, less than 2 mm thick) that is not mentioned by Lull (1904, 1915, 1953), has one manus and possibly one pes track of such poor quality that analytic comparison to the type of A. flexiloquus is impossible. Therefore, the ichnogenus Antipus has a single species, A. flexiloquus, known only from the type specimen, AC 41/52. Two of the eleven tracks on AC 41/52 have been illustrated (Hitchcock 1858, plate 20, fig. 10; republished with minor revision by Lull 1915, fig. 117; these two tracks are here designated M2 and P4). These simple outline sketches do not accurately portray details of the tracks, and the full trackway pattern was not illustrated.

This paper describes new species of Ostracoda from Late Cretaceous (late Santonian) oyster reefs of the Eutaw Formation of eastern Alabama. The reefs are composed almost exclusively of Ostrea cretacea Morton, with rarer occurrences of the oysters Exogyra upatoiensis Stephenson and Lopha ucheensis (Stephenson) and the bivalve Anomia preolmstedi Stephenson. Total thickness of the reefs is about 30 m, and the reefs are a major topographic feature across most of Macon and Russell Counties, Alabama, a distance of about 60 km. The reefs are interpreted to have been backbarrier sediments deposited under brackish conditions.

Eight species of ostracodes are identified, including five new species described herein. The fauna is typically well preserved, and includes males, females, and juveniles. New species include Haplocytheridea? eutawensis, Antibythocypris dimorphicus, A. nephotrema, Brachycythere asymmetrica, and Eocytheropteron mutafoveata. Also discussed and illustrated are Cytherella tuberculifera Alexander, Haplocytheridea renfroensis renfroensis Crane, and Fissocarinocythere gapensis (Alexander).

Conodont faunas with species of Ancyrodella are described from the upper Penn Yan Shale (Crosby Sandstone) and Genundewa Limestone of the middle Genesee Formation between Keuka Lake and Lake Erie. Three established species and three new species in the early phylogeny of Ancyrodella are discussed: A. rotundiloba (Bryant) early form, A. rotundiloba late form, A. crosbiensis n. sp., A. recta n. sp., A. triangulata n. sp., A. rugosa Branson and Mehl, and A. alata? Glenister and Klapper. Standardization of the taxonomic concepts pertaining to these species (and others in the genus) is necessary to ensure their continued biostratigraphic usefulness. The sequence of faunas in New York correlates well with the lower Frasnian sequence and numbered conodont zones described by Klapper (1985, 1989) in the Montagne Noire, France. A fauna with the late form of Ancyrodella rotundiloba and A. crosbiensis n. sp. in the Crosby Sandstone of the upper Penn Yan Shale correlates with Zone 2 of Klapper (1989). The Crosby fauna succeeds a Zone 1 fauna with the early form of Ancyrodella rotundiloba in the lower Penn Yan Shale. The Crosby fauna is succeeded in turn by a fauna in the upper Genundewa Limestone with A. recta n. sp., A. triangulata n. sp., A. rugosa, and A. alata?, which is correlated with Zone 3 even though the zonal markers, A. alata sensu stricto and typical forms of A. rugosa, first occur in the lower part of the overlying West River Shale.

Multivariate morphometric analysis was applied for differentiation of closely related species and evaluation of intra- and interspecific variation in Manipora from the Selkirk Member, Red River Formation, in southern Manitoba. Seven morphological characters were quantified in transverse thin sections of 46 coralla and statistically tested for selecting effective characters in discriminating species. Cluster analysis was performed on a raw data matrix coordinated with 46 coralla by three selected characters. Two major clusters on the resulting dendrogram were regarded as morphospecies, following comparative examination of the coralla using serial sections. Cluster analyses were also conducted on principal component score matrices obtained from the raw data set coordinated with 46 coralla by all seven characters, and from an experimental data set including the 46 coralla plus two replicates of each and six of the characters. the results agree closely with the first cluster analysis, but discrimination of morphospecies was slightly degraded. the validity of two morphospecies recognized in the first cluster analysis was verified by discriminant analyses, descriptive statistics, and bivariate plots. the results show that tabularium area is the most meaningful character for distinguishing these morphospecies; ranges of variations of the other six characters overlap between morphospecies.

Another cluster analysis like the first was performed, but with the addition of 11 type specimens and reference coralla of Manipora species from the Upper Ordovician of southern and northern Manitoba and Texas. Based on this analysis, together with comparative examination of thin sections, the two morphospecies are identified as valid species: M. amicarum Sinclair, 1955 and M. manitoba (Sokolov, 1955). Manipora magna Flower, 1961 is considered to be a synonym of M. amicarum, while M. trapezoidalis Flower, 1961 and M. garsonensis Caramanica, 1992 are considered to be synonyms of M. manitoba, and the hypotypes of M. amicarum of Nelson (1963) are assigned to M. manitoba.

Cyriacotheriidae are a family of unusual small-bodied pantodonts known from the Paleocene of the Western Interior of North America. Cyriacotheriids possess a suite of dental characters similar to that of pantodonts (e.g., molar dilambdodonty, lingual molar hypoconulids), as well as several divergent features (e.g., molarized premolars, strong molar conules) that have been interpreted as “dermopteran-like.” the unusual combination of pantodont and dermopteran-like characters, combined with a limited fossil record, has made attempts at understanding the broader relationships of Cyriacotheriidae difficult. This paper reports on a new genus and two new species of cyriacotheriids from the Paleocene of Alberta, Canada, with both species significantly older than those of the only previously described cyriacotheriid, Cyriacotherium. Collectively, the dentitions of these new taxa exhibit derived characters seen in Cyriacotherium (e.g., robust molar conules, strong molar dilambdodonty) in addition to a number of plesiomorphies seen in more basal pantodonts (e.g., conspicuous molar entoconids, deep premolar ectoflexus) and, importantly, posterior premolars that are weakly molariform and non-dilambdodont. A phylogenetic analysis of the new cyriacotheriid, basal pantodonts, dermopterans, and dermopteran-like eutherians resulted in Cyriacotheriidae nesting within a monophyletic Pantodonta. the results strengthen previous hypotheses regarding the pantodont affinities of the family, and suggest that the dermopteran-like features seen in the more derived Cyriacotherium were acquired convergently. Although the discovery of new cyriacotheriids sheds light on the evolutionary history of the family, it cannot resolve the ongoing questions of pantodont origins; nonetheless, their discovery in strata of early Paleocene age indicates that significant parts of the evolutionary history of Cyriacotheriidae, and North American pantodonts more generally, have yet to be discovered.

Re-evaluation of teeth referred to the Late Cretaceous shark Ptychodus polygyrus from North America are hereby determined to be synonymous with another species having similar tooth morphology, Ptychodus marginalis Agassiz. Ptychodus marginalis differs from P. polygyrus by having an elevated and rounded tooth crown with transverse ridges restricted centrally on the apex of the crown with a clearly defined marginal area. The type specimen of P. marginalis was described from Middle Cenomanian to Middle Turonian deposits in the English Chalk, and teeth possessing identical tooth morphologies are found within contemporary units in North America, whereas teeth having the typical P. polygyrus morphology are restricted to Late Santonian-Early Campanian deposits.

Clusters of associated colony fragments discovered weathering out of bedding planes in the Upper Ordovician of the Cincinnati, Ohio, region provide a rare opportunity to quantify intracolony variation in ramose stenolaemate bryozoans. Sixteen colonies were reassembled as completely as possible from 198 fragments, and the following colony-level characters were measured: colony dimensions, branch link length and diameter, and branch order. Results indicate that branch link length and diameter systematically decrease as colonies grow via branch bifurcation. Branching ratio (i.e., the number of distal first-order branches divided by the number of immediately proximal second-order branches) appears to be more genetically than environmentally controlled and to be consistent among orders of stenolaemates and perhaps across the phylum. Colonies with endozones mined out by endoskeletozoans result in broken branches as opposed to pristine growing tips. This varies stratigraphically, perhaps in response to the distribution of the boring animals. The rarity of borers and the systematic proximal increase in branch diameter in these colonies suggest the zooids in the proximal portions of the colonies were alive at the time of colony death. If the time and effort can be invested in reassembling colonies, these morphometric data can then be applied to taxonomic, phylogenetic, and paleoenvironmental studies.

Plesiadapiforms represent the first radiation of Primates, appearing near the Cretaceous-Paleogene boundary. Eleven families of plesiadapiforms are recognized, including the Paromomyidae. Four species of paromomyids from the early Eocene have been reported from Europe: Arcius fuscus Russell et al., 1967, Arcius lapparenti Russell et al., 1967, and Arcius rougieri Godinot, 1984 from France and Arcius zbyszewskii Estravís, 2000 from Portugal. Other Arcius specimens from the early Eocene are known from Masia de l’Hereuet (Spain), Abbey Wood (England), and Sotteville-sur-Mer (Normandy, France). A cladistic analysis of the European paromomyids has never previously been published. A total of 53 dental characters were analyzed for the four Arcius species and the specimens from Spain, England, and Normandy. The results of a parsimony analysis using TNT agree with previous conceptions of A. zbyszewskii as the most primitive member of the genus. Consistent with existing hypotheses, Arcius rougieri is positioned as the sister taxon of A. fuscus and A. lapparenti, and the results suggest that the fossil from Normandy is A. zbyszewskii. However, the English fossil pertains to a primitive lineage, rather than grouping with A. lapparenti as had been suggested; as such it is recognized here as a distinct species (Arcius hookeri new species). The Spanish fossils cluster together with the French species but do not show the previously proposed special relationship with A. lapparenti and are sufficiently distinct to be placed in a new species (Arcius ilerdensis). Arcius is recovered as monophyletic, which is consistent with a single migration event from North America to Europe around the earliest Eocene through the Greenland land bridge.

UUID: http://zoobank.org/f4aac438-82d2-4a25-887b-3e0c072d87f6