Obsidian projectile point conveyance patterns in the lower Humboldt Valley, Nevada (Anthropological papers of the American Museum of Natural History, number 105)

134 pages : illustrations (some color), color maps ; 26 cmDespite their ubiquity, surface occurrences of obsidian artifacts at archaeological sites throughout western North America have traditionally been viewed as unworthy of serious attention because of the difficulty in dating them. In the past 40 years, the time sensitivity of certain Great Basin projectile point types has been established, which brings the importance of surface collections more center stage. With the coming of age and refinement of geochemical methods, obsidian artifacts from these surface sites can now be analyzed using nondestructive instrumental methods and matched to their geological eruptive origin on the basis of congruence in trace and rare earth element chemistry. Many of these surface assemblages in the Great Basin contain considerable numbers of obsidian projectile points that, when matched to their chemical source of origin, open up entirely new ways to investigate change and continuity in past land use and social relations. The present study was conducted in the lower Humboldt Valley of western Nevada, where large numbers of obsidian projectile points have been collected by professional archaeologists over the past century and housed in academic institutions and museums. In this study, more than 900 obsidian projectile points and bifaces were analyzed from 24 sites and localities within the lower Humboldt Valley using energy-dispersive X-ray fluorescence (EDXRF) to bring data to bear on the question of whether changes in obsidian source use occurred there over the past 5000 years (as determined by time-sensitive projectile points). Significant changes were identified in the direction and distance-to-source of arrow points vs. dart points, and in the source and direction of Humboldt series points and of Humboldt Basal-notched bifaces, which implicate directional shifts through time in social relations among peoples using—and during some periods living at sites in—the lower Humboldt Valley. These results provide independent data to evaluate current views about land use, artifact conveyance, social relations, and technological change in the western Great Basin and beyond

Modularity in the trilobite head consistent with hypothesized segmental origin of the eyes

Landmark data, R-script, and associated files for modularity analyses of Calyptaulax annulata and Cloacaspis senilis

Bundles of sperm : structural diversity in scorpion sperm packages illuminates evolution of insemination in an ancient lineage (American Museum novitates, no. 3993)

50 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

Systematic review and cranial osteology of Petersius with redescription of P. conserialis (Teleostei: Alestidae) from the Rufiji and Ruvu rivers of Tanzania (American Museum novitates, no. 3992)

16 pages : illustrations (some color), color map ; 26 cmWe review the systematics of the monotypic alestid genus Petersius and provide a taxonomic redescription of P. conserialis from eastern Tanzania. Morphological investigation includes direct observation and examination of radiographed and μCT-scanned data from type and non-type specimens. We delimit the taxon’s geographic distribution along the lowland regions of the Rufiji and Ruvu river basins in Tanzania and provide information on ecology, sexual dimorphism, and ontogenetic variation. Petersius is herein diagnosed by the possession of a unique cuspidation patterning of the inner-row premaxillary dentition and a distinctively shaped anterodorsal margin of the supraoccipital crest. It shares with some species of Phenacogrammusa sigmoid-shaped process on the dorsal margin of the second infraorbital, a feature lacking in other alestid taxa. Additional features of potential utility for ongoing investigation of relationships among alestid genera include the possession of contralateral premaxillae separated by the anteromedial process of the mesethmoid and without interdigitations connecting the medial surfaces of the premaxillae; four, occasionally five or six, small outer-row premaxillary teeth implanted alternately with those of the inner row; a dentary lacking a pair of conical inner-row teeth proximal to the symphysis; a dorsal posttemporal fossa that is smaller than the ventral fossa; a median third posttemporal fossa located entirely within the epioccipital; a truncate dorsomedial cranial fontanel; and a complete circumorbital series forming an uninterrupted ring around the orbit in adult specimens

Supplemental Material for 'Cavioids, chinchilloids, and erethizontoids (Hystricognathi, Rodentia, Mammalia) of the early Miocene Pampa Castillo fauna, Chile. (American Museum novitates, no. 3984)'

Supplemental Material for 'Cavioids, chinchilloids, and erethizontoids (Hystricognathi, Rodentia, Mammalia) of the early Miocene Pampa Castillo fauna, Chile. (American Museum novitates, no. 3984)

Revision of the Nearctic species of the genus Amiota Loew (Diptera: Drosophilidae) (Bulletin of the American Museum of Natural History, no. 458)

177 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

Craniodental morphology and phylogeny of marsupials (Bulletin of the American Museum of Natural History, no. 457)

350 pages : illustrations (some color) ; 26 cm.The current literature on marsupial phylogenetics includes numerous studies based on analyses of morphological data with limited sampling of Recent and fossil taxa, and many studies based on analyses of molecular data with dense sampling of Recent taxa, but few studies have combined both data types. Another dichotomy in the marsupial phylogenetic literature is between studies focused on New World taxa and those focused on Sahulian taxa. To date, there has been no attempt to assess the phylogenetic relationships of the global marsupial fauna based on combined analyses of morphology and molecular sequences for a dense sampling of Recent and fossil taxa. For this report, we compiled morphological and molecular data from an unprecedented number of Recent and fossil marsupials. Our morphological data consist of 180 craniodental characters that we scored for 97 terminals representing every currently recognized Recent genus, 42 additional ingroup (crown-clade marsupial) terminals represented by well-preserved fossils, and 5 outgroups (nonmarsupial metatherians).Our molecular data comprise 24.5 kb of DNA sequences from whole-mitochondrial genomes and six nuclear loci (APOB, BRCA1, GHR, RAG1, RBP3 and VWF) for 97 marsupial terminals (the same Recent taxa scored for craniodental morphology) and several placental and monotreme outgroups. The results of separate and combined analyses of these data using a wide range of phylogenetic methods support many currently accepted hypotheses of ingroup (marsupial) relationships, but they also underscore the difficulty of placing fossils with key missing data (e.g., †Evolestes), and the unique difficulty of placing others that exhibit mosaics of plesiomorphic and autapomorphic traits (e.g., †Yalkaparidon). Unique contributions of our study are (1) critical discussions and illustrations of marsupial craniodental morphology including features never previously coded for phylogenetic analysis; (2) critical assessments of relative support for many suprageneric clades; (3) estimates of divergence times derived from tip-and-node dating based on uniquely taxon-dense analyses; and (4) a revised, higher-order classification of marsupials accompanied by lists of supporting craniodental synapomorphies. Far from the last word on these topics, this report lays the foundation for future research that may be enabled by the discovery of new fossil taxa, better-preserved material of previously described taxa, novel morphological characters (e.g., from the postcranium), and improved methods of phylogenetic analysis

Description of two new species of Apomecynini (Coleoptera, Cerambycidae, Lamiinae) (American Museum novitates, no. 3985)

10 pages : color illustrations, map ; 26 cm.Two new species of cerambycid beetles are described and illustrated: Morrisia skillmani from Guatemala and Adetaptera jejetama from Mexico. Additionally, a map illustrating the geographic distribution of the species of Morrisia Santos-Silva et al., 2019, and a key to the species of the genus are provided

Evolution in Rhinella (Anura: Bufonidae)

155 pages : illustrations (some color) ; 26 cm.True toads of the genus Rhinella are among the most common and diverse group of Neotropical anurans. These toads are widely distributed throughout South America, inhabiting a great diversity of environments and ecoregions. Currently, however, the genus is defined solely on the basis of molecular characters, and it lacks a proper diagnosis. Although some phenetic species groups have traditionally been recognized within Rhinella, the monophyly of some of them have been rejected in previous phylogenetic analyses, and many species remain unassigned to these poorly defined groups. Additionally, the identity and taxonomy of several species are problematic and hinder the specific recognition and description of undescribed taxa. In this work, we first perform phylogenetic analyses of separate mitochondrial and nuclear datasets to test the possible occurrence of hybridization and/or genetic introgression in the genus. The comparative analysis of both datasets revealed unidirectional mitochondrial introgressions of an unknown parental species into R. horribilis ("ghost introgression") and of R. dorbignyi into R. bernardoi; therefore, the mitochondrial and nuclear datasets of these species were considered separately in subsequent analyses. We performed total-evidence phylogenetic analyses that included revised molecular (four mitochondrial and five nuclear genes) and phenotypic (90 characters) datasets for 83 nominal species of Rhinella, plus several undescribed and problematic species and multiple outgroups. Results demonstrate that Rhinella was nonmonophyletic due to the position of R. ceratophrys, which was recovered as the sister taxon of Rhaebo nasicus with strong support. Among our outgroups, the strongly supported Anaxyrus + Incilius is the sister clade of all other species of Rhinella. Once R. ceratophrys is excluded, the genus Rhinella is monophyletic, well supported, and composed of two major clades. One of these is moderately supported and includes species of the former R. spinulosa Group (including R. gallardoi); the monophyletic R. granulosa, R. crucifer, and R. marina Groups; and a clade composed of the mitochondrial sequences of R. horribilis. The other major clade is strongly supported and composed of all the species from the non-monophyletic R. veraguensis and R. margaritifera Groups, the former R. acrolopha Group, and R. sternosignata. Consistent with these results, we define eight species groups of Rhinella that are mostly diagnosed by phenotypic synapomorphies in addition to a combination of morphological character states. Rhinella sternosignata is the only species that remains unassigned to any group. We also synonymize nine species, treat three former subspecies as full species, and suggest that 15 lineages represent putative undescribed species. Lastly, we discuss the apparently frequent occurrence of hybridization, deep mitochondrial divergence, and "ghost introgression"; the incomplete phenotypic evidence (including putative character systems that could be used for future phylogenetic analyses); and the validity of the known fossil record of Rhinella as a source of calibration points for divergence dating analyses

Cranial morphology and phylogenetic relationships of Trigonostylops wortmani, an Eocene South American native ungulate (Bulletin of the American Museum of Natural History, no. 449)

183 pages : illustrations (some color) ; 26 cm.In 1933 George G. Simpson described a remarkably complete skull of Trigonostylops, an Eocene South American native ungulate (SANU) whose relationships were, in his mind, quite uncertain. Although some authorities, such as Florentino Ameghino and William B. Scott, thought that a case could be made for regarding Trigonostylops as an astrapothere, Simpson took a different position, emphasizing what would now be regarded as autapomorphies. He pointed out a number of features of the skull of Trigonostylops that he thought were not represented in other major clades of SANUs, and regarded these as evidence of its phyletic uniqueness. Arguing that the lineage that Trigonostylops represented must have departed at an early point from lineages that gave rise to other SANU orders, Simpson reserved the possibility that Astrapotheriidae might still qualify (in modern terms) as its sister group. Even so, he argued that the next logical step was to place Trigonostylops and its few known allies in a separate order, Trigonostylopoidea, coordinate with Astrapotheria, Notoungulata, Litopterna, and Pyrotheria. Simpson's classification was not favored by most later authors, and in recent decades trigonostylopids have been almost universally assigned to Astrapotheria. However, his evaluation of the allegedly unique characters of Trigonostylops and its allies has never been systematically treated, which is the objective of this paper. Using computed tomography, the skull of Trigonostylops is compared, structure by structure, to a variety of representative SANUs as well as extant perissodactylans (which together comprise the clade Panperissodactyla) and the "condylarthran" Meniscotherium. In addition to placing Simpson's character evaluations in a comparative context, we also provide detailed assessments of many vascular and pneumatization-related feature of panperissodactylans never previously explored. Overall, we found that this new assessment strengthened the placement of Trigonostylops within a monophyletic group that includes Astrapotherium and Astraponotus, to the exclusion of other SANU clades. Although Trigonostylops cannot be considered as morphologically distinct or unusual as Simpson thought, our comparative and phylogenetic analyses have helped to generate a number of hypotheses about character evolution and function in SANUs that may now be fruitfully tested using other taxon combinations