{"title":"Intraspecific Variation through Ontogeny in Late Cretaceous Ammonites","authors":"C. Klein, N. Landman","doi":"10.1206/3922.1","DOIUrl":"https://doi.org/10.1206/3922.1","url":null,"abstract":"ABSTRACT This project assesses intraspecific variation through the ontogeny of the ammonite Scaphites whitfieldi Cobban, 1951, from the Upper Cretaceous of the U.S. Western Interior. Our sample consists of 103 dorsoventral cross sections from nine localities that represent two lithofacies (shale and siltstone). We measured four shell parameters (ww/dm, ww/wh, uw/ dm, and WER) to describe the ontogenetic changes in shell morphology. We investigated the variation at three growth stages: immediately after hatching (dm = 1 mm), the neanoconch (dm = 4 mm), and the submature stage (defined as at or near the base of the mature hooklike body chamber). In general, the shell becomes more discoidal through ontogeny with a narrower umbilicus and a more compressed whorl section. The results of the univariate analysis indicate that the variation is statistically significantly higher in the neanoconch than in either the hatchling or submature stage. This pattern is also apparent in the multivariate analysis in which the disparity increases markedly from the hatchling to the neanoconch and then decreases again at the submature stage. These results are consistent with the hypothesis that the neanoconch represents a transition in the life history of the animal to a more demersal mode of life followed by a canalization of morphology toward maturity. However, because the neanic transition occurs over a range of sizes, it is possible that some individuals may have already undergone these changes at dm = 4 mm, whereas others may not have, thus inflating the degree of variation. To resolve this issue in the future, it is critical to examine each ontogenetic trajectory individually to pinpoint the exact size at which the morphological changes occur. We also compared the values of ww/dm, ww/wh, uw/dm, and WER of the three growth stages for the sample from siltstone versus the sample from shale. The comparison reveals that the specimens from siltstone occupy lower regions of the morphospace, implying that these specimens are generally more compressed than those from shale. This difference may be related to selection pressures for improved hydrodynamic efficiency in the higher energy environment represented by siltstone.","PeriodicalId":55527,"journal":{"name":"American Museum Novitates","volume":"2019 1","pages":"1 - 25"},"PeriodicalIF":1.5,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42654743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Neotype for Didelphis marsupialis Linnaeus, 1758","authors":"Â. Feijó, R. Voss","doi":"10.1206/3923.1","DOIUrl":"https://doi.org/10.1206/3923.1","url":null,"abstract":"ABSTRACT Didelphis marsupialis, type species of the genus Didelphis, is a widely distributed and commonly studied American marsupial. Unfortunately, the previously noncontroversial application of the epithet marsupialis Linnaeus, 1758, has recently been called into question, and the lectotype is no longer extant. To preserve long-standing binomial usage for this species and other congeneric taxa, we designate a specimen from Surinam in the Royal Ontario Museum as neotype.","PeriodicalId":55527,"journal":{"name":"American Museum Novitates","volume":" ","pages":"1 - 12"},"PeriodicalIF":1.5,"publicationDate":"2019-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48827178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The Phylogenetic Relationships of Cretaceous Biting Midges, with a Key to All Known Genera (Diptera: Ceratopogonidae)","authors":"A. Borkent","doi":"10.1206/3921.1","DOIUrl":"https://doi.org/10.1206/3921.1","url":null,"abstract":"ABSTRACT The phylogenetic positions of Cretaceous species of Ceratopogonidae previously placed in the genera Archiculicoides Szadziewski, Protoculicoides Boesel, and Atriculicoides Remm are reappraised in light of synapomorphies. Character states are discussed in detail, supported by new photographs of Protoculicoides depressus Boesel, the description of Protoculicoides revelatus, n. sp., from Burmese amber, and a compilation of previously published illustrations. The recent article by Szadziewski et al. (2016) proposing that Protoculicoides and Atriculicoides are congeneric is shown to be inaccurate. At least three separate lineages are represented by species in these two genera, requiring a new genus, Gerontodacus (type species, G. succineus (Szadziewski)), to include some of them. Archiculicoides, Protoculicoides, Gerontodacus, Adelohelea Borkent and Alautunmyia Borkent remain undetermined to subfamily. As a result of phylogenetic and other taxonomic considerations, the following are new combinations: Gerontodacus krzeminskii (Choufani, Azar, and Nel), Gerontodacus punctus (Borkent), Gerontodacus skalskii (Szadziewski and Arillo), Archiaustroconops andersoni (Szadziewski, Ross, and Giłka), Atriculicoides ciliatus (Borkent), Atriculicoides hispanicus (Szadziewski and Arillo), Atriculicoides sanjusti (Szadziewski and Arillo) and Adelohelea burmitica (Szadziewski and Poinar). The following species are returned to the genera they were assigned to before Szadziewski et al. (2016): Atriculicoides cenomanensis Szadziewski and Schlüter, Atriculicoides dasyheleis Szadziewski, Atriculicoides globosus (Boesel), Atriculicoides incompletus Szadziewski and Schlüter, Atriculicoides macrophthalmus Remm, Atriculicoides sibiricus Szadziewski, Atriculicoides swinhoei (Cockerell), Atriculicoides szadziewskii Pérez-de la Fuente, Delclòs, Peñalver, and Arillo and Atriculicoides taimyricus Szadziewski. A key is provided to all Cretaceous Ceratopogonidae genera.","PeriodicalId":55527,"journal":{"name":"American Museum Novitates","volume":"2019 1","pages":"1 - 48"},"PeriodicalIF":1.5,"publicationDate":"2019-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45691522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hollister W. Herhold, S. Davis, C. Smith, M. Engel, D. Grimaldi
{"title":"Unique Metasomal Musculature in Sweat Bees (Hymenoptera: Apoidea: Halictidae) Revealed by Micro-CT Scanning","authors":"Hollister W. Herhold, S. Davis, C. Smith, M. Engel, D. Grimaldi","doi":"10.1206/3920.1","DOIUrl":"https://doi.org/10.1206/3920.1","url":null,"abstract":"ABSTRACT Bees of the family Halictidae (Apoidea: Anthophila) have three pairs of thick, bundled muscles that are circular to subcircular in cross section within the first metasomal segment, as revealed by micro-CT scanning of 16 species in 15 genera of five bee families. In nonhalictids and the basal halictid subfamily Rophitinae, these muscles are planar (flat and sheetlike), typically lying between the anterior air sacs and abdominal wall. In Nomiinae and Halictinae, these muscles, especially the dorsal-ventral pair, bulge into air-sac space, partly enveloped by air-sac membrane. A possible function may be to facilitate metasomal compression and contraction, and thus air flow. The bundled shape of these derived halictid muscles is similar to that of flight muscles, but further data is needed to determine if they are fibrillar, which would suggest a completely different function.","PeriodicalId":55527,"journal":{"name":"American Museum Novitates","volume":" ","pages":"1 - 28"},"PeriodicalIF":1.5,"publicationDate":"2019-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48543036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. R. Carvalho, A. Giaretta, A. Angulo, C. Haddad, P. Peloso
{"title":"A New Amazonian Species of Adenomera (Anura: Leptodactylidae) from the Brazilian State of Pará: A Tody-Tyrant Voice in a Frog","authors":"T. R. Carvalho, A. Giaretta, A. Angulo, C. Haddad, P. Peloso","doi":"10.1206/3919.1","DOIUrl":"https://doi.org/10.1206/3919.1","url":null,"abstract":"ABSTRACT Leptodactylid frogs are phenotypically diverse, widely distributed across the Neotropics, and are known to harbor high levels of cryptic species diversity. This is especially true in Adenomera, where several candidate species have been recognized in a genetics-based study. Here we describe a new Amazonian species of Adenomera, which corresponds to one of the lineages previously identified as a candidate species (“sp. F”). Adenomera phonotriccus, n. sp., differs from all 18 recognized congeners by its unique advertisement call. Moreover, this species can be distinguished from nearly all congeners (except A. cotuba and A. lutzi) in having antebrachial tubercles on the undersides of its forearms. The distribution of A. phonotriccus seems to be restricted to the Araguaia- Xingu interfluve, in the eastern portion of the Brazilian state of Pará. Additional sampling effort on the right margin of the Araguaia River and along the Xingu River drainage should clarify the distribution of A. phonotriccus and perhaps result in the discovery of additional undescribed species of Adenomera in a region with high biological diversity.","PeriodicalId":55527,"journal":{"name":"American Museum Novitates","volume":"3919 1","pages":"1 - 21"},"PeriodicalIF":1.5,"publicationDate":"2019-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45184425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Russell K. Engelman, J. J. Flynn, P. Gans, A. Wyss, D. Croft
{"title":"Chlorocyon phantasma, a Late Eocene Borhyaenoid (Mammalia: Metatheria: Sparassodonta) from the Los Helados Locality, Andean Main Range, Central Chile","authors":"Russell K. Engelman, J. J. Flynn, P. Gans, A. Wyss, D. Croft","doi":"10.1206/3918.1","DOIUrl":"https://doi.org/10.1206/3918.1","url":null,"abstract":"ABSTRACT Sparassodont metatherians were the dominant terrestrial mammalian predators during South America's long Cenozoic isolation. This group's early fossil record is very poor, however, particularly for the late Eocene and early Oligocene. Here, we describe a new sparassodont, Chlorocyon phantasma, gen. et sp. nov., based on a specimen from Los Helados, a new locality within the Abanico Formation of the Andean Main Range of central Chile. New 40Ar/39Ar dates at Los Helados bracketing the fossil-bearing level constrain the age of this specimen to 37–36 Ma (late Eocene), indicating that this new taxon likely pertains to the Mustersan South American Land Mammal “Age.” Chlorocyon is the first Paleogene sparassodont reported from Chile and the first sparassodont described from the Abanico Formation. Distinctive features, including a p3 with an anterior edge that is more curved than the posterior edge and the lack of a hypoconulid on m4, suggest that Chlorocyon is a borhyaenoid closely related to Pharsophorus or Plesiofelis, although much smaller. Chlorocyon represents a welcome addition to the sparse record of late Eocene sparassodonts and indicates that the diversity of non-proborhyaenid borhyaenoids prior to the late Oligocene was greater than previously thought.","PeriodicalId":55527,"journal":{"name":"American Museum Novitates","volume":"1 1","pages":"1 - 22"},"PeriodicalIF":1.5,"publicationDate":"2018-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1206/3918.1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46397999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A New Small Barb (Cyprininae: Smiliogastrini) from the Louesse, Lekoumou (Upper Niari Basin), and Djoulou (Upper Ogowe Basin) Rivers in the Republic of Congo, West-Central Africa","authors":"V. Mamonekene, A. Zamba, M. Stiassny","doi":"10.1206/3917.1","DOIUrl":"https://doi.org/10.1206/3917.1","url":null,"abstract":"ABSTRACT A new species of smiliogastrin cyprinid is described from the Louesse, Lekoumou (upper Niari basin), and Djoulou (upper Ogowe basin) rivers in the Republic of Congo, west-central Africa. The new species is readily distinguished from congeners by the presence of a flexible, weakly ossified and smooth bordered last unbranched dorsal-fin ray, well-developed barbels, and a straight and complete lateral line in combination with a characteristic pigmentation patterning consisting of a distinctive, rounded black spot at the base of and extending over the first rays of the anal fin and a prominent, darkly pigmented blotch over the base of the anterior dorsal-fin rays. A combination of morphological features and pigmentation patterning that appears to be unique among Enteromius. The new species is widespread throughout the Louesse-Djoulou region, and the fact that such a seemingly common species has gone undetected until now serves to underscore how poorly known this region of the Republic of Congo remains.","PeriodicalId":55527,"journal":{"name":"American Museum Novitates","volume":"1 1","pages":"1 - 16"},"PeriodicalIF":1.5,"publicationDate":"2018-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42341597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Morgan, Nancy A. Albury, R. Rímoli, Phillip Lehman, A. Rosenberger, S. Cooke
{"title":"The Cuban Crocodile (Crocodylus rhombifer) from Late Quaternary Underwater Cave Deposits in the Dominican Republic","authors":"G. Morgan, Nancy A. Albury, R. Rímoli, Phillip Lehman, A. Rosenberger, S. Cooke","doi":"10.1206/3916.1","DOIUrl":"https://doi.org/10.1206/3916.1","url":null,"abstract":"ABSTRACT Late Quaternary fossils representing a locally extinct population of the Cuban crocodile (Crocodylus rhombifer) are reported from two underwater caves in the Dominican Republic. A large fossil sample of C. rhombifer, from Oleg's Bat Cave near Bavaro in the southeastern Dominican Republic, consists of four nearly complete skulls, numerous isolated cranial elements and mandibles, and more than 100 postcranial bones representing most of the skeleton. These fossils were collected from a completely submerged portion of the cave at a depth of 11 m and about 100 m from the nearest entrance. A skull, mandibles, and two vertebrae of a Cuban crocodile were also found in a second cave called Ni-Rahu, northeast of Santo Domingo. We identify the fossil crocodile skulls from the Dominican Republic as Crocodylus rhombifer because they share the following characters with modern skulls of C. rhombifer from Cuba (as well as fossil skulls from Cuba, the Bahamas, and Cayman Islands): short, broad, and deep rostrum; large orbits; convex nasals along the midline (midrostral boss); prominent swelling on the lacrimals anterior and medial to the orbits; low but obvious ridges extending anteriorly from the lacrimals to the nasals and posteriorly from the lacrimals to the prefrontals and frontals, outlining a distinct diamond- or rhomboid-shaped structure; strongly concave interorbital region and cranial roof; high, narrow ridges on the internal margins of the orbits, extending from the prefrontals to the frontals and posteriorly to the postorbitals; prominent ridges along the lateral margins of the cranial roof on the postorbitals and squamosals, terminating as noticeable protuberances on the posterolateral corners of the squamosals; premaxillary/maxillary suture on the palate essentially horizontal or transverse to the long axis of the skull at the level of the first maxillary tooth; 13 teeth in the maxilla. Certain aspects of the ecology and anatomy of living Crocodylus rhombifer in Cuba, and carbon isotope data from fossil crocodile bones from both the Dominican Republic and the Bahamas, indicate that the Cuban crocodile is a terrestrially adapted predator. The fossil deposits in Oleg's Bat Cave and other underwater caves in the Dominican Republic lack freshwater vertebrates, such as fish and turtles, but contain abundant samples of hystricognath rodents, small ground sloths, and other terrestrial vertebrates, including large land tortoises, that apparently were the primary prey of the crocodiles. Bats are abundant in the fossil deposits in Oleg's Bat Cave, and may have been an additional food source. Bone collagen from a tibia of C. rhombifer from Oleg's Bat Cave yielded an AMS radiocarbon date of 6460 ±30 ryrBP (equivalent to 7320 to 7430 cal yrBP). The chronology for the local extinction of C. rhombifer in Hispaniola is currently unknown, except to document the presence of this species in the eastern Dominican Republic in the early Holocene. Radiocarbon dat","PeriodicalId":55527,"journal":{"name":"American Museum Novitates","volume":"1 1","pages":"1 - 56"},"PeriodicalIF":1.5,"publicationDate":"2018-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1206/3916.1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43696817","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Amorim, S. S. Oliveira, Andrea C. Henao-sepúlveda
{"title":"A New Species of Eumanota Edwards (Diptera: Mycetophilidae: Manotine) from Colombia: Evidence for a Pseudogondwanan Pattern","authors":"D. Amorim, S. S. Oliveira, Andrea C. Henao-sepúlveda","doi":"10.1206/3915.1","DOIUrl":"https://doi.org/10.1206/3915.1","url":null,"abstract":"ABSTRACT Eumanota wolffae, sp. nov., is described from the high Andean forests of Colombia. This is the first Neotropical species of the clade of non-Manota genera of the mycetophilid subfamily Manotinae—to date known entirely from the Oriental and the northwestern Australasian regions, and in Baltic amber. With the other species of Eumanota Edwards, this species shares, among other features, a largely developed third maxillary palpomere, projecting beyond the base of fourth palpomere, with a wide sensorial pit, a flat inner face, and the last palpomere at least 4× the length of the fourth palpomere. The systematic position of the Colombian species within the Manotinae is addressed. The biogeographic significance of Eumanota in the Neotropical region is discussed, interpreted here as a concurrent incidence of a circumtropical pattern and Gondwanan distributions, in other words, a particular pattern of biogeographic pseudocongruence, referred to here as a “pseudogondwanan pattern.” This pattern is associated with an early Cenozoic tropical biota over Laurasian terranes that expanded its distribution to the south (in the Americas, Africa, and Australasia), followed by large-scale extinction of Nearctic and Palearctic representatives due to global cooling in the Neogene. A discussion is provided about the correlation between these patterns and evidence of Late Cretaceous-Paleogene tropical floras over Laurasian terranes.","PeriodicalId":55527,"journal":{"name":"American Museum Novitates","volume":"2018 1","pages":"1 - 19"},"PeriodicalIF":1.5,"publicationDate":"2018-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47647306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Bai, Yuanqing Wang, Qian Li, Haibing Wang, Fangyuan Mao, Yan-Xin Gong, Jin Meng
{"title":"Biostratigraphy and Diversity of Paleogene Perissodactyls from the Erlian Basin of Inner Mongolia, China","authors":"B. Bai, Yuanqing Wang, Qian Li, Haibing Wang, Fangyuan Mao, Yan-Xin Gong, Jin Meng","doi":"10.1206/3914.1","DOIUrl":"https://doi.org/10.1206/3914.1","url":null,"abstract":"ABSTRACT Extant perissodactyls (horses, rhinos, and tapirs) comprise a small portion of living mammals, but fossil perissodactyls were more diverse and commonly dominated Paleogene faunas. Unfortunately, the taxonomy and distribution of some Chinese Paleogene perissodactyls remain controversial and unclear, hampering the correlation of Asian paleofaunas with paleofaunas from other continents. Here we clarify the temporal and spatial distribution of Paleogene perissodactyl species from the Erlian Basin based on published specimens, archives, and our recent fieldwork. The strata of the Erlian Basin range nearly continuously from the late Paleocene to the early Oligocene, and almost all Eocene Asian Land Mammal Ages (ALMA) are based on corresponding faunas from the Erlian Basin. We revise the most complete section of deposits at Erden Obo (= Urtyn Obo) that range in age from the late Paleocene to the early Oligocene in the Erlian Basin, and correlate it with other type formations/faunas in the basin based mainly on the perissodactyl biostratigraphy and lithostratigraphy. Furthermore, we discuss perissodactyl faunal components and their diversity from the early Eocene to the early Oligocene in the Erlian Basin, as well as the correlation between middle Eocene ALMAs and North American Land Mammal Ages based on perissodactyl fossils. The general decrease in perissodactyl diversity from the middle Eocene to the late Eocene can probably be attributed to a global climatic cooling trend and related environmental changes. The diversity of perissodactyls declined distinctly during the Eocene-Oligocene Transition, when global average temperatures dropped considerably.","PeriodicalId":55527,"journal":{"name":"American Museum Novitates","volume":"1 1","pages":"1 - 60"},"PeriodicalIF":1.5,"publicationDate":"2018-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1206/3914.1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42333898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}