Abstract Like ants, termites are entirely eusocial and have profound ecological significance in the tropics. Following upon recent studies reporting more than a quarter of all known fossil termites, we present the first phylogeny of termite lineages using exemplar Cretaceous, Tertiary, and Recent taxa. Relationships among Recent families were largely unaffected by the addition of extinct taxa, but the analysis revealed extensive grades of stem-group taxa and the divergence of some modern families in the Cretaceous. Rhinotermitidae, Serritermitidae, and the “higher” termites (family Termitidae), which comprise 84% of the world termite species, diverged and radiated entirely in the Tertiary, corresponding to a significant increase in termite individuals in the fossil record. Radiation of the higher termites may have affected the formation of terrestrial carbon reserves like oil and coal. The higher classification of Isoptera is slightly revised based on the phylogenetic results. The following new taxa are p...
The Balnibarbiinae is one of eight subfamilies of the Olenidae, a diverse family of late Cambrian to Ordovician trilobites. Balnibarbiine species occur in a relatively continuous section of deeper-water sediments exposed along the northeastern coastline of Spitsbergen, Svalbard, as well as scattered deeper-water beds in central Nevada. Results of phylogenetic analyses of the subfamily using both parsimony and Bayesian methods are consistent with a previous hypothesis based on phyletic similarity and stratigraphic range. Cloacaspis Fortey, 1974, is supported as monophyletic, but the support for Balnibarbi Fortey, 1974, is weak, and the genus may be paraphyletic to Cloacaspis even with the reassignment of Balnibarbi ceryx Fortey, 1974, to Cloacaspis. New field collections and discovery of previously undescribed material in museum and survey collections provides the basis for emended descriptions of the genus Cloacaspis, as well as Cloacaspis tesselata Fortey and Droser, 1999, Cloacaspis ekphymosa Fortey, 1974, and Balnibarbi erugata Fortey, 1974, and expands the geographic range of the subfamily to Alaska.
Relationships among Neoaves, a group comprising approximately 95% of all extant birds, are difficult to resolve because of multiple short internodes presumably created by a rapid evolutionary radiation around the K/Pg boundary. This difficulty has plagued both morphological and molecular studies. Compared with molecular studies with extensive taxon and character sampling, morphological datasets have largely failed to provide insight into the phenotypic evolutionary transitions of the neoavian radiation. Extinct neoavian taxa remain an understudied but critical key to resolving relationships among these problematic stem lineages and understanding evolutionary changes in structure and function. Adzebills (Aptornis), some of the most phylogenetically controversial fossil neoavians, are extinct terrestrial birds endemic to New Zealand since at least the early Miocene. Past morphological studies have placed adzebills as a sister taxon to the flightless Kagu of New Caledonia (Rhynochetos juhatus) or to the land- and waterfowl group Galloanseres. Recent molecular studies reveal the Kagu and Sunbittern (Eurypyga helias) to be sister taxa, whereas adzebills have been postulated to be within Rallidae (rails, gallinules, and coots) or the sister taxon of Sarothruridae (flufftails) or Ralloidea (finfoots, flufllails, and rails). To better resolve the position of adzebills and begin constructing a finescale total evidence phylogenetic dataset for the base of Neoaves, we constructed a new and more comprehensive morphological dataset of 368 discrete osteological characters for 38 extant and two extinct taxa that includes extensive sampling of nearly all neoavian stem lineages. We then combined this dataset with 32 DNA sequences of the slowly evolving nuclear RAG1 and RAG2 genes. Morphological results place adzebills as the sister taxon of trumpeters (Psophia) within core Gruiformes and confirm strong support for a Kagu+Sunbittern sister group (99% bootstrap value). Results for analyses of the combined data were identical, and the adzebill+trumpeter Glade was supported by a 99% Bayesian Glade credibility value. Although the Kagu+Sunbittern sister group is consistent with recent molecular hypotheses, the adzebill+trumpeter group is novel.
Karyotypes are described for six species of snakes from the Western Hemisphere, and comparisons are made with all species of snakes from around the world that have been karyotyped with modern methods. Although there is significant karyotypic variation in snakes, there is one basic karyotype that is shared by members of all families of snakes, representing widely divergent lineages, extending from today back through the evolutionary history of the Serpentes. Long-term survival of the ancestral snake karyotype may be a result of canalization, similar to some ancient chromosomes of turtles.
A lower jaw was recently discovered in a limestone concretion in association with the Late Cretaceous (Turonian) ammonite Spathites puercoensis (Herrick and Johnson, 1900) from the Carlile Member of the Mancos Shale in Sandoval County, New Mexico. It is nearly complete and comprises the aptychus with a hinge along the midline. The better-preserved plate, the left (according to its position in life), is roughly triangular in shape with a broadly rounded lateral margin, a narrowly rounded posterior margin, and a weakly concave anterior margin. It is 26.2 mm wide and 33.0 mm long. Together, the left and right plates form an escutcheonlike shape that projects slightly forward at the apex. The ratio of jaw width to length (26.2 mm x 2 / 33.0 mm) equals 1.59. The aptychus consists of yellow-orange calcite and is covered with comarginal ribs that parallel the lateral and posterior margins and become more prominent toward the posterior end. It is likely that this jaw belongs to the associated ammonite and would have comfortably fit inside the body chamber, based on a comparison of the length of the jaw and the whorl height, suggesting that it functioned as a jaw, rather than as an operculum. It is the first report of an ammonite jaw in the genus Spathites and the first reported occurrence of an ammonite jaw from New Mexico.
This paper describes the eggs and last larval instars of certain species of bees belonging to the tribe Meliponini, one of the four related tribes that comprise the corbiculate bees in the subfamily Apinae. The four taxa analyzed include some whose immature stages have previously been described. Our purpose is to identify what is known about the anatomy of immature stages and suggest what needs to be studied to better understand the developmental anatomy of eggs and mature larvae in this group of highly eusocial bees.
Didelphis marsupial is, 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.
This study explores egg eclosion and larval biology of orchid bees (Apidac: Euglossini) in light of existing knowledge from studies dealing with a group of tribes within the Apidae referred to as corbiculate bees. It reports that Eulaema (Apeulaema) polychroma (Mocsary) has five larval instars, and its first instar exists only briefly in that with the help of a band of spicules along both of its sides its exoskeleton is shed with the remnants of the chorion. Mature larvae of euglossines exhibit two anatomical features that are not characteristic of other corbiculates, namely the elongate, tapering area of the prothorax immediately behind the head and the small size of the cranium. These features are suggested to be accommodations allowing the development of the extremely long labiomaxillary region of the pupa, which in turn accounts for the lengthy mouthparts of the adult. Descriptions of the egg and mature larva of Euglossa (Euglossa) hemichlora Cockerell are appended as well as referenced in the text.
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.
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 Gilka), 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 Schluter, Atriculicoides dasyheleis Szadziewski, Atriculicoides globosus (Boesel), Atriculicoides incompletus Szadziewski and Schluter, Atriculicoides macrophthalmus Remm, Atriculicoides sibiricus Szadziewski, Atriculicoides swinhoei (Cockerell), Atriculicoides szadziewskii Perez-de la Fuente, Delclos, Penalver, and Arillo and Atriculicoides taimyricus Szadziewski. A key is provided to all Cretaceous Ceratopogonidae genera.
This contribution results from an investigation of four commercially obtained colonies of Bombus (Pyrobombus) impatiens Cresson in an attempt to understand the functional anatomy and behavior of its immature stages. Eggs are described in detail, and their chorionic micro- structure is contrasted with that of Bombus (Cullumanobombus) griseocollis (De Geer). They are deposited in groups consisting of a few to more than nine eggs into a single chamber. The study confirms that larvae pass through four instars. Although increasing in size dramatically from one instar to the next, larval anatomy and behavior change little during the first three instars. The last instar is the one that commences defecation and production of silk resulting in cocoon construction. In contrast to most bees, its larval activities result in substantial changes in size and shape of its brood chamber, whereas brood chambers of most bees are constructed by the female and modified little by the offspring. This study is a part of a series of investigations into the similarities and differences in the developmental biologies among corbiculate bees.
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.
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 Para. 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.
The wings of insects are one of their most prominent features and embody numerous characters and modifications congruent with the variety of their lifestyles. However, despite their evolutionary relevance, homology statements and nomenclature of wing structures remain understudied and sometimes confusing. Early studies on wing venation homologies often assumed Neuropterida (the superorder comprising the orders Raphidioptera, Megaloptera, and Neuroptera: snakeflies, alderflies and dobsonflies, and lacewings) to be ancient among Pterygota, and therefore relied on their pattern of venation for determining groundplans for insect wing venation schemata and those assumptions reciprocally influenced the interpretation of lacewing wings. However, Neuropterida are in fact derived among flying insects and thus a reconsideration of their wings is crucial. The identification of the actual wing venation of Neuropterida is rendered difficult by fusions and losses, but these features provide systematic and taxonomically informative characters for the classification of the different clades within the group. In the present study, we review the homology statements of wing venation among Neuropterida, with an emphasis on Chrysopidae (green lacewings), the family in which the highest degree of vein fusion is manifest. The wing venation of each order is reviewed according to tracheation, and colored schemata of the actual wing venation are provided as well as detailed illustrations of the tracheation in select families. According to the results of our study of vein tracheation, new homology statements and a revised nomenclature for veins and cells are proposed.
As a companion to the tribal-level phylogenetic analysis of Phylinae by Menard, Schuh, and Woolley (2013), a comprehensive generic classification of the subfamily is presented. Names used in the work of Menard et al. (2013) at the tribal/subtribal levels are documented in accordance with the International Code of Zoological Nomenclature (1999). The new tribal-level names Coatonocapsina, Decomiini, Exocarpocorini, Keltoniina, and Tuxedoina are introduced; the long unused or seldom-used tribal-level names Cremnorrhini Reuter, 1883, Exaeretina Puton, 1975, Nasocorini Reuter, 1883, Oncotylina Douglas and Scott, 1865, and Semiini Knight, 1923, are used and rediagnosed; Phylini Douglas and Scott, 1865, is given a more narrow conception than in previous classifications and the subtribe Phylina is recognized; Pilophorini Douglas and Scott, 1865, is conceived more broadly to include Lasiolabops Poppius and Dilatops Weirauch; Auricillocorini Schuh, 1984, is treated as a junior synonym of Hallodapini Van Duzee; and Pronotocrepini Knight, 1929, is treated as a junior synonym of Cremnorrhina, Reuter, 1883. Comments are made on some of the genera included in the analyses of Menard et al. (2013) and arguments are presented for the placement of all remaining genera of Phylinae, some of which are placed as incertae sedis particularly within Phylina because of insufficient evidence to place them with confidence in any currently recognized tribe/subtribe. Lapazphylus Carvalho and Costa, 1992, is treated as a junior synonym of Nicholia Knight,. 1929; Schuhistes Menard, 2010, is treated as a junior synonym of Parasciodema Poppius, 1914; Linacoris Carvalho, 1983, is transferred from the Orthotylinae to Phylinae, Hallodapini; and the status of Parapsallus Wagner, 1952, is revised.
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 Ar-40/(39) Ar 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.
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.
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 dates and historical records confirm that Cuban crocodiles survived into the period of European colonization (post-1492) in the Bahamas and on Grand Cayman. The only species of crocodile currently found in Hispaniola, the American crocodile (C. acutus), occurs in coastal marine habitats and in two inland brackishwater lakes: Lago Enriquillo in the Dominican Republic and the nearby Etang Saumatre in Haiti. C. acutus has no fossil record in Hispaniola or elsewhere in the West Indies, suggesting that this species may be a very recent (late Holocene) immigrant in the Antillean region. Crocodylus rhombifer has one of the most limited geographic ranges of any living crocodylian species, known only from freshwater swamps in south-central Cuba and the Isla de Juventud (Isla de Pinos) off the southwestern coast of Cuba. Locally extinct or extirpated populations of C. rhombifer from fossil deposits in the Dominican Republic, Grand Cayman, and the Bahamas document a considerably wider distribution for this species during the Late Quaternary.
Eumanota wolffae, sp. nov., is described from the high Andean forests of Colombia. This is the first Neotropical species of the Glade 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 4x 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.