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Revision of the Nearctic species of the genus Amiota Loew (Diptera: Drosophilidae) (Bulletin of the American Museum of Natural History, no. 458)
Full text link177 pages : illustrations (some color), color maps ; 26 cmThorough biotic inventories are still needed even in families with paradigm organisms like Drosophilidae, including well-studied areas such as North America. This work presents a taxonomic revision of the species of the genus Amiota Loew in North America and the Nearctic portion of Mexico. Amiota steganoptera Malloch is currently excluded from the Nearctic and Amiota setigera Malloch is synonymized under Amiota humeralis Loew. Specimens of Amiota subtusradiata Duda were not encountered during this study along with its synonym Amiota quadrata Takada and Toda; however, based on previous descriptions we include A. subtusradiata in the Nearctic fauna. All other previously described species from the Nearctic are redescribed. Thirty-six species are described as new: Amiota amputata, A. antitormentum, A. avipes, A. biacuminis, A. brayi, A. byersi, A. cervites, A. cruciatum, A. didens, A. durangoensis, A. elsaltoensis, A. floridiensis, A. forceps, A. fulvitibia, A. hyalou, A. imperator, A. incurva, A. laevifurca, A. latilabrum, A. mcalpinei, A. multiplex, A. nanonigrescens, A. occidentalis, A. onyx, A. oviraptor, A. pseudominor, A. raripennis, A. sinaloensis, A. subnebojsa, A. tessae, A. texas, A. tibialis, A. tormentum, A. uniacuminis, A. wheeleri, and A. zaliskoi. This increases the total species known in the Nearctic from 13 to 49. All species in the Nearctic are illustrated, adult diagnostic features are discussed, and distributions are provided. A cladogram based on parsimony analysis of 46 morphological characters established species groups in the genus. Most of the Nearctic species were accommodated into 10 species groups. Three species groups were previously erected for species in China and Europe. Seven species groups are newly established: the avipes, cervites, hsui, mariae, nebojsa, nigrescens, and subtusradiata groups.Diversity in Amiota appears to be partially dependent on elevation and latitude in the Nearctic, with high diversity found in southern Ontario, the Appalachians, the Ozarks, mountain forests of Arizona and New Mexico, and the Sierra Madre of central Mexico. The taxonomic history of the Nearctic species is reviewed, and various aspects of their biology is presented. Males of species in the A. mariae species group are polymorphic for mirror-image, asymmetric genitalia, called chiral variants. Besides morphology, larval saproxyly, adult lachryphagy, and biogeography are reviewed. Challenges to the study of Amiota and future prospects are discussed
New diminutive Eocene lizard reveals high K-Pg survivorship and taxonomic diversity of stem xenosaurs in North America (American Museum novitates, no. 3986)
No full text36 pages : illustrations (some color), color map ; 26 cm.We describe a new diminutive early Eocene lizard, Blutwurstia oliviae, gen. et sp. nov., on the basis of associated cranial and postcranial remains from the Clarks Fork Basin of Wyoming. Results from phylogenetic analyses suggest that B. oliviae is on the stem of knob-scaled lizards (Xenosaurus), a relict extant clade of specialized, stenotopic crevice-dwellers from Mexico and Central America. Results further suggest that B. oliviae is basal to all other previously described pan-xenosaurs (members of Pan-Xenosaurus, the total clade of Xenosaurus) except species of Entomophontes, to which it is closely related. Given that B. oliviae and Entomophontes are known from a limited fossil record, with only one recovered element (the maxilla) in common, the level of support for this relationship is surprisingly high. We use a posteriori time-calibrated trees and ghost lineages (maximum parsimony) and divergence time estimates under the fossilized birth-death process (Bayesian inference) to infer patterns of extinction across the Cretaceous-Paleogene (K-Pg) boundary in Pan-Xenosaurus, including those consistent with pseudoextinction. Whereas the fossil record documents a single lineage in the latest Cretaceous, results from analyses using these analytical methods suggest that three or more species existed, with high survivorship across the K-Pg boundary. The surviving lineages were apparently present at proximal to intermediate distance from the Chicxulub impact site, thought to have a causal relationship with extinctions across the K-Pg boundary. The premaxilla and dorsal vertebrae of E. incrustatus and B. oliviae, respectively, independently suggest that each of these taxa had a depressed body form consistent with extant crevice-dwelling squamates, which may have played a role in the high survivorship of pan-xenosaur lineages across the K-Pg boundary
Cavioids, chinchilloids, and erethizontoids (Hystricognathi, Rodentia, Mammalia) of the early Miocene Pampa Castillo fauna, Chile (American Museum novitates, no. 3984)
No full text46 pages : illustrations (some color) ; 26 cm.Caviomorph rodents became important components of South American faunas after their Eocene arrival from Africa. Here we describe the cavioid, chinchilloid, and erethizontoid caviomorphs of the early Miocene Pampa Castillo fauna of southern Chile. This fauna’s age and location make it key for resolving outstanding biostratigraphic questions concerning early Miocene Patagonian fossiliferous strata. Each of the four major caviomorph clades (“superfamilies”) is represented in the Pampa Castillo fauna, three whose members are detailed here: cavioids (3 genera; 3 species), chinchilloids (3 genera; 6 species), and erethizontoids (2 genera; 2 species). Abundantly represented taxa, e.g., Neoreomys australis, Perimys erutus, and Prolagostomus pusillus, corroborate previous work assigning the Pampa Castillo fauna to the Santacrucian South American Land Mammal “Age” (SALMA; inclusive of the “Pinturan”). Several taxa, including Eosteiromys, Perimys intermedius, and Perimys sp. nov.?, are also found in the lower and middle Pinturas Formation (lmPF) but not “core” Santacrucian faunas (from the Santa Cruz Formation [SCF] along the Río Santa Cruz and Atlantic coast), suggesting a distinctive resemblance between lmPF and Pampa Castillo rodents. Some authors consider the fauna from the lmPF to form the basis of a “Pinturan” SALMA or subage, considered to slightly predate core Santacrucian faunas, but which has yet to be formally recognized. The taxonomic composition of rodent fauna from Pampa Castillo, as well as relative abundance data, indicated a paleoenvironment intermediate between the closed forests of the lmPF and the mosaic of open and closed habitats of the core Santacrucian faunas from the SCF
Spatial and temporal distribution of the island-dwelling Kogaionidae (Mammalia, Multituberculata) in the uppermost Cretaceous of Transylvania (Western Romania) (Bulletin of the American Museum of Natural History, no. 456)
Full text link109 pages : illustrations (chiefly color), maps ; 26 cm.The latest Cretaceous kogaionid multituberculates from Transylvania (western Romania) were part of an endemic European clade of mammals that underwent an insular radiation at the end of the Cretaceous and then survived the end-Cretaceous mass extinction that extinguished many groups of contemporary therians. Transylvanian kogaionids lived on what was an island during the latest Cretaceous—“Hațeg Island”—and their fossils are found in the uppermost Campanian to upper Maastrichtian deposits of the Hațeg, Rusca Montană, and southwestern Transylvanian basins. This fossil record has improved dramatically over the past several decades, in part resulting from our decade-long joint Romanian-American-Scottish fieldwork, and comprises one of the most impressive and complete archives of Mesozoic mammals, including not only jaws and teeth but several incomplete skulls and partial skeletons.We here review the fossil record of kogaionids from Transylvania. We report four new occurrences from the Hațeg Basin, update information on previously described ones, and use our database to reassess the chronostratigraphical and geographical distribution of kogaionids and their evolutionary patterns. Although it was previously suggested that large and small kogaionids had largely mutually exclusive spatial distributions, we recognize the cooccurrence of small and large taxa in various units, suggesting a sympatric distribution across their entire chronostratigraphic range. We also identify a novel pattern: small kogaionids appear somewhat earlier than their larger relatives in all well-sampled sedimentary successions, suggesting that kogaionid colonizations of Hațeg Island and component regions took place at small body size and that body size increased only later through local evolution. We find correlations between body size, preservation style, and sedimentary context, which give insight into kogaionid paleobiology and diversity. Larger kogaionids are represented more often by partial skulls and occasionally skeletons compared with small kogaionids, which are usually represented only by isolated teeth, regardless of provenance. Larger kogaionids currently have a higher recognized local taxic diversity than their smaller relatives. We hypothesize that this may be in part a consequence of preservational bias related to body size, as more complete specimens may be more easily diagnosed as distinct taxa than those that are represented by more fragmentary and/or incomplete fossils. If true, the taxic diversity of smaller kogaionids may currently be underestimated. Finally, we identify correspondence between sedimentary facies and preservation style. Red-colored fine-grained rocks, suggestive of well-drained, oxidized floodplain paleoenvironments, yield more complete specimens than drab, greenish or grayish sediments deposited in more poorly drained parts of the floodplain. This pattern may suggest habitat preferences for better-drained floodplain environments and a semifossorial lifestyle for some taxa. As the kogaionid fossil record improves, we can further test the hypotheses and patterns outlined above. The pace of new kogaionid discoveries by our team and others indicates that a more complete picture of kogaionid distribution, paleobiology, and evolution will emerge in the coming years, contributing to a more profound understanding of this peculiar group of island-dwelling Mesozoic mammals
The itineraries of Alfred Crossley, and natural history collecting in mid-nineteenth century Madagascar (American Museum novitates, no. 3987)
No full text25 pages : map ; 26 cm.Alfred Crossley was one of the most prolific collectors of natural history specimens in Madagascar during the 19th century, with several vertebrate species named for him and numerous vertebrate and invertebrate holotypes to his credit. Yet the details of his life, and even of his professional activities, have been almost completely lost to history. Here I assemble what is known of Crossley’s Madagascar itineraries in the years between 1869 and 1877, with the aim of providing a basis for more precisely pinpointing his many collecting localities. With the aid of a newly rediscovered obituary and contemporary press extracts, I also outline the details of a productive and drama-filled life that began with shipwreck and captivity in Madagascar and ended in a lonely death there, possibly under dubious circumstances. I also seek to understand why Crossley attracted so little attention while doing such visible and significant work, concluding that this lack of recognition was due partly to humble social origins in an era of gentlemen scientists and partly to an exceedingly retiring personal disposition
An annotated checklist of Recent opossums (Mammalia: Didelphidae) (Bulletin of the American Museum of Natural History, no. 455)
Full text link74 pages ; 26 cm.Living opossums (Didelphidae) comprise 125 species in 18 genera and 4 subfamilies. This synopsis lists all the didelphid taxa (subfamilies, tribes, genera, subgenera, and species) currently recognised as valid, summarizes information about typification, synonyms, and geographic distributions, remarks noteworthy recent changes in usage, and comments on still outstanding problems. A concluding discussion rejects the notion that the almost twofold increase in opossum species from 1993 to the present is “taxonomic inflation” and considers the impact of new kinds of data and new methods of data analysis on species delimitation
Bundles of sperm : structural diversity in scorpion sperm packages illuminates evolution of insemination in an ancient lineage (American Museum novitates, no. 3993)
No full text50 pages : illustrations ; 26 cm.The spermatozoa of scorpions are often bundled together, forming a type of sperm conjugation known as a sperm package. Sperm packages may be found inside the testes and seminal vesicles but vanish in the female atrium, leaving free spermatozoa. Previous studies, based on a limited number of taxa, suggested a diversity of sperm package morphology across the order Scorpiones C.L. Koch, 1850. However, the sperm packages of most scorpion taxa remained unknown. The present study provides the first systematic survey of sperm package morphology across the order, covering 89 exemplar species in 66 genera and 19 families representing all suprafamilial ranks, with a more detailed investigation of the family Bothriuridae Simon, 1880. Whereas all exemplar species of scorpions exhibit sperm packages, Buthida Soleglad and Fet, 2003, including Chaerilidae Pocock, 1893, and most Buthidae C.L. Koch, 1837, present unorganized sperm or loosely organized bundles. Although the details vary, three main types of sperm packages may be recognized in all other families: single folded; straight; and multiple folded. Subtypes may be identified according to general shape and folding patterns, mainly among sperm packages that are folded multiple times. Single-folded sperm packages are the most common type observed in the order. Although most sperm packages lack a covering, a conspicuous secretion sheath may be evident, e.g., in some Chactidae Pocock, 1893. Sperm packages vary in length from 112–354 μm and bent sperm packages are not necessarily longer than straight sperm packages. Four exemplar species of Bothriuridae reveal that variation in sperm count within a single sperm package is consistent with the count derived in spermatogenesis. The diversity of sperm packages suggests a path from free spermatozoa, via bent sperm packages, to other forms. Sperm packages may aid in the transport, cooperation, competition, and survival of spermatozoa. The diverse morphology, function, and evolution of sperm packages merit further investigation
A new species of air-breathing catfish (Clariidae: Clarias) from Salonga National Park, Democratic Republic of the Congo (American Museum novitates, no. 3990)
No full text20 pages : illustrations (chiefly color), color map ; 26 cmA new species of air-breathing catfish, Clarias monsembulai, is described from Congo River tributaries within and bordering the Salonga National Park (Democratic Republic of the Congo). The new taxon is recognized by its exceptionally long, white barbels, which lend a superficial resemblance to Clarias buthupogon, from which it differs in characters of the cleithrum and pigmentation patterning. We suggest placement of this species into the subgenus Clarioides but note the current dearth of morphological data to unite members of this group. We additionally discuss the validity of the subspecies Clarias angolensis macronema
A new dichromatic species of Myotis (Chiroptera: Vespertilionidae) from the Nimba Mountains, Guinea (American Museum novitates, no. 3963)
No full text37 pages : color illustrations ; 26 cm.The genus Myotis is a diverse group of vespertilionid bats found on nearly every continent. One clade in this group, the subgenus Chrysopteron, is characterized by reddish to yellowish fur and, in some cases, visually striking dichromatic wing pigmentation. Here, we describe a new dichromatic species of Myotis (Chrysopteron) from the Nimba Mountains in Guinea. The new species is superficially similar to Myotis welwitschii, but phylogenetic analyses based on cytochrome b data indicated that it is actually more closely related to M. tricolor. Discovery of this new taxon increases the number of Myotis species known from mainland Africa to 11 species, although patterns of molecular divergence suggest that cryptic species in the Chrysopteron clade remain to be described. This discovery also highlights the critical importance of the Nimba Mountains as a center of bat diversity and endemism in sub-Saharan Africa
Deep-sea anemones (Cnidaria: Anthozoa: Actiniaria) from the South Atlantic (Bulletin of the American Museum of Natural History, no. 444)
Full text link69 pages : illustrations (chiefly color), color map ; 26 cm.Brazil has the longest coastline in South America with more than 7491 km of hydrologically and topologically complex continental margin. Despite its extensive coast, the sea anemone fauna of the country is sparsely known with only 54 species recorded. Difficulties of accessing Brazil's highly diversified coast and the historical small number of dredging expeditions and sea anemone taxonomists have contributed to the limited knowledge of its sea anemone diversity particularly in deep waters. Most species recorded from Brazil correspond to large, conspicuous intertidal species and only five species have been recorded from depths greater than 200 m: two small burrowing edwardsiids and three hormathiids from the southern coast of Brazil. Here, we provide complete descriptions, images of external and internal anatomy, microanatomy, cnidae, and geographic distribution for 10 species, six off the coast of Brazil and four from the southern portion of the Mid-Atlantic Ridge, one of which is also present in the Southern Ocean. Four of the six species found in Brazil represent new records of geographically widespread species for the country and the remaining two endemic species have their geographic and bathymetric ranges significantly extended northward. As a result, the number of species known for the Brazilian coast is raised to 63 species, 14 of which are known from the deep sea. We also recorded four deep-sea species in the south Mid-Atlantic Ridge (SMAR), including Actinernus mercedae, sp. nov., and two new records for the South Atlantic. We found that the deep-sea fauna of Brazil shares two deep-sea species with Argentina and two with the North Atlantic. Thus, La Plata River acts as a filter for shallow water species between Brazil and Argentina but is less effective for deep-sea anemones. The diversity of sea anemones recorded for SMAR shows similarities to the southwestern Atlantic and Southern Ocean. Finally, our finding of representatives of Bolocera in the SMAR and Actinoscyphia off the Brazilian coast suggests that they are bipolar genera with tropical emergence