Sawfishes and Other Elasmobranch Assemblages from the Mio-Pliocene of the South Caribbean (Urumaco Sequence,Northwestern Venezuela)

The Urumaco stratigraphic sequence, western Venezuela, preserves a variety of paleoenvironments that include terrestrial, riverine, lacustrine and marine facies. A wide range of fossil vertebrates associated with these facies supports the hypothesis of an estuary in that geographic area connected with a hydrographic system that flowed from western Amazonia up to the Proto-Caribbean Sea during the Miocene. Here the elasmobranch assemblages of the middle Miocene to middle Pliocene section of the Urumaco sequence (Socorro, Urumaco and Codore formations) are described. Based on new findings, we document at least 21 taxa of the Lamniformes, Carcharhiniformes, Myliobatiformes and Rajiformes, and describe a new carcharhiniform species (†Carcharhinus caquetius sp. nov.). Moreover, the Urumaco Formation has a high number of well-preserved fossil Pristis rostra, for which we provide a detailed taxonomic revision, and referral in the context of the global Miocene record of Pristis as well as extant species. Using the habitat preference of the living representatives, we hypothesize that the fossil chondrichthyan assemblages from the Urumaco sequence are evidence for marine shallow waters and estuarine habitats.     

The world’s largest gharialsGryposuchus: description ofG. croizati n. sp. (Crocodylia, Gavialidae) from the Upper Miocene Urumaco Formation, Venezuela

A new fossil gharialGryposuchus species is described from the Upper Miocene Urumaco Formation, Venezuela.Gryposuchus croizati new species can be distinguished from other gavialoids, includingGryposuchus colombianus andGryposuchus neogaeus by the following combination of diagnostic characters: 1) slenderness of the parietal interfenestral bar; 2) dental formula, mainly the lesser number of maxillary teeth, with four premaxillary, 19 maxillary and 22 mandibular teeth; 3) large width of palatines between the reduced palatine fenestrae; 4) medial hemicondyle of the quadrate smaller but detached and much more posteriorly elongated than the lateral one and projected ventromedially; 5) pterygoid morphology, with two posterior vacuities. The polymorphism in the contour of the external naris inGryposuchus was evaluated for taxonomic significance. The body size ofG. croizati n. sp. was estimated in 10.15 m (9.67–10.67 m) using the dorsal skull length and the estimation of the body mass was 1,745 kg (1,280–2,379 kg) based on the braincase length. These maximal values placeG. croizati n. sp. among the world’s largest gharials and even Crocodyliforms as a whole.      

Establishment of the exotic parasiteTetrastichus haitiensis [Hym.: Eulophidae] and recovery of a newTrichogramma [Hym.: Trichogrammatidae] from root weevil egg masses in Florida

The exotic root weevil egg parasite,Tetrastichus haitiensis Gahan, imported from Puerto Rico and released in Florida between 1969 and 1971, was found established on citrus root weevil egg masses in 1978 near Oakhill, Florida. It was also recovered there from field-collected weevil egg masses from June to August 1978 and from citrus bouquets containing egg masses placed in the grove during July and August 1978. In addition, a new species ofTrichogramma was discovered. In the laboratory, this species parasitized egg masses of 4 species of weevils that attack citrus in Florida. These areDiaprepes abbreviatus (L.),Pachnaeus litus (Germar),P. opalus (Olivier) andArtipus floridanus Horn.     

A new species of Litarachna (Acari,Hydrachnidia, Pontarachnidae) from a Caribbean mesophotic coral ecosystem

New records of pontarachnid mites (Acari: Hydrachnidia) from the Caribbean island of Puerto Rico are presented. Litarachna lopezae sp. n., from substrata collected from Bajo de Sico, a mesophotic coral reef ecosystem in Mona Passage off Puerto Rico, is described as new to science. The new species was collected from nearly 70 m depth, the greatest depth from which pontarachnid mites have been found until now. In addition, a Litarachna sp. was also found in association with the tube of the polychaete Sabellastarte magnifica (Shaw, 1800) at the shallow waters of north Puerto Rico.     

A compsemydid turtle from the Upper Cretaceous of Var,southern France

Calissounemys matheroni gen. et sp. nov. (Testudines) is described on the basis of a skull and shell elements from the Upper Cretaceous of Var, southern France. This new taxon is assigned to the family Compsemydidae and characterized by a thick-boned, robust skull, a shallow temporal emargination, a crista supraoccipitalis not extending beyond the posterior edge of the skull roof, large nasals meeting along the midline for their full length; frontals retracted from the orbital margin, absence of a cheek emargination, a large jugal forming a substantial part of the orbital margin, absence of a secondary palate and an uneven upper triturating surface; and the shell with vertebral 1 clearly wider than vertebrals 2-3, with the lateral margins strongly divergent towards the anterior border and wider than long vertebrals 2-3. This find increases the diversity of the Late Cretaceous turtle fauna from southern France, and fills a stratigraphical gap in the fossil record of Compsemydidae between the Early Cretaceous and the Paleocene in Europe.     

Genetic analysis of a novel invasion of Puerto Rico by an exotic constricting snake

The tropical island Puerto Rico is potentially vulnerable to invasion by some species of exotic snakes; however, until now no established populations had been reported. Here we report and genetically characterize the nascent invasion of Puerto Rico by an exotic constricting snake of the family Boidae (Boa constrictor) using mtDNA and microsatellite data. Over 150 individual B. constrictor have been removed from Mayagüez municipality since May 2011, and our results from the genetic analysis of 32 individuals suggest that this population was recently founded by individuals of one subspecies from a genetic lineage common to zoo and breeding collections, but that the potential propagule pool consists of two subspecies. We also suggest that anthropogenic long-distance dispersal within the island of Puerto Rico may be occurring from the established population, with implications for further establishment across the island. This study represents the first report of the naturalization of an invasive species of boid snake in Puerto Rico and will be important in determining mitigation strategies for this invasion as well as providing a basis for comparison to other on-going studies of invasive snakes.     

Mosasaurus beaugei Arambourg, 1952 (Squamata, Mosasauridae) from the Late Cretaceous phosphates of Morocco

Mosasaurus beaugei Arambourg, 1952 was based on isolated teeth from the Maastrichtian phosphatic deposits of Morocco. The recent discovery of new material, including skull and mandibular remains, improves our knowledge of this species. M. beaugei shares the following synapomorphies with the genus Mosasaurus: large teeth bearing two prominent carinae and with asymmetrical labial and lingual surfaces, the labial one being flattened and strongly facetted and the lingual one being convex; premaxillae with a small pointed rostrum and dentary without rostrum; palatal elements closely united; coronoid with very large ventromedial process overlying the prearticular. M. beaugei is characterised by the following autapomorphies: 12-13 maxillary teeth; marginal teeth bearing 3-5 prisms on the labial surface and 8-9 on the lingual one; palatine with posterior border concave and perpendicular to the long axis of the skull; splenial visible laterally on half of the dentary ventral surface; coronoid with anterior wing well developed and bearing two notches. M. beaugei is only known to date in the Maastrichtian phosphates of Morocco.     

New microsatellite markers for the ectomycorrhizal fungus Pisolithus tinctorius sensu stricto reveal the genetic structure of US and Puerto Rican populations

The ectomycorrhizal fungus Pisolithus tinctorius has been introduced to many areas around the world as a source of inoculum for pine plantations. However, little is known about the genetic structure of fungal populations in their introduced habitats. To study the genetics of exotic P. tinctorius populations, we developed and employed seven new microsatellite markers and compared samples from Puerto Rico (exotic range) and the eastern United States (native range). Bayesian cluster analysis, neighbor joining analysis and F_ST values all strongly separated Puerto Rican populations from North American populations. Consistent with a founder effect, populations from Puerto Rico had reduced allelic richness when compared to samples from the United States. The genetic structure of P. tinctorius populations in Puerto Rico is weak to modest and is not correlated with geographic distance reflecting anthropogenic movement of inoculum with forestry practices.     

There goes the neighborhood: apparent competition between invasive and native orchids mediated by a specialist florivorous weevil

The exotic orchid, Spathoglottis plicata, has naturalized and spread rapidly over Puerto Rico where it is generally considered to be innocuous. It is abundant and occupies the same habitat as the native orchid, Bletia patula. The two are hosts to the same native weevil, Stethobaris polita, a specialist on orchid flowers. We ask whether the weevils mediate apparent competition between the two orchids. We monitored weevil populations, floral damage and fruit set in B. patula in the presence and absence of S. plicata. We also experimentally tested whether weevils preferred one species over the other. Finally, we modeled the distribution of both orchid species to predict the extent by which the two species may interact in Puerto Rico. We found a significantly lower number of weevils and a higher fruit set for B. patula where S. plicata is absent, indicative that apparent competition is occurring. The choice experiments show that weevils prefer flowers of S. plicata over those of B. patula, but B. patula still sustained considerable damage. The current distribution of the native B. patula is nearly limited to the northern karst region of Puerto Rico. The naturalized S. plicata has a broader range and the models predict that its distribution will strongly overlap with that of B. patula. We expect the S. plicata invasion to continue and affect native orchids through apparent competition as long as the presence of S. plicata maintains elevated weevil populations. Thus, even seemingly harmless invasive orchids can have subtle but significant negative consequences.     

Four New Ladybug Species Belonging to Decadiomus Chapin (Coleoptera: Coccinellidae) from Puerto Rico

While searching for native natural enemies attacking invasive insect pests in Puerto Rico, we found four undescribed ladybug species belonging to the Caribbean ladybug genus Decadiomus Chapin. In this article, we describe the following species from Puerto Rico: Decadiomus seini n. sp., Decadiomus ramosi n. sp., Decadiomus hayuyai n. sp., and Decadiomus martorelli n. sp. Illustrations of the dorsal habitus, shape of prosternal carinae, and drawings of male and female genitalia are presented. We also present a key for Diomini of Puerto Rico and discuss their importance as potential biocontrol agents.     

On a cranial bony nodular protuberance on Mourasuchus pattersoni Cidade et al. 2017 (Crocodylia,Alligatoroidea) from the late Miocene of Venezuela

Mourasuchus pattersoni, from the late Miocene Urumaco Formation of Venezuela, is the fourth and most recent species described for the genus. The holotype, and only known specimen, is comprised of an almost complete skull with both mandibular rami and several postcranial remains. In ventral view, the right palatine bone has a spherical, nodular bony protuberance located on the anterior portion, near the suture with the maxilla. Unfortunately, we cannot assign a specific diagnosis based only on macroscopic inspection. Its appearance, form and location are compatible with three conditions: torus palatinus, a common benign intraoral bone overgrowth; osteoma, a benign neoplasical overgrowth of the bone; and hamartoma, an overgrowth of normal bone tissue that can only be differed from an osteoma by histological features. While occurrences of torus palatinus or hamartomas are not yet known in the nonhominid vertebrate fossil record, there are previous records of osteomas in fossil vertebrates, including in crocodylians, such as a specimen assigned to ‘Crocodylus sp.’ from the Eocene, aside from several records for living crocodylians. Future studies are needed to uncover an accurate diagnosis of this unusual structure and help increase our knowledge of paleopathology in fossil crocodylomorphs in general, especially in the Caimaninae clade.     

Occurrence ofByronia Matthew andSphenothallus Hall in the Lower Cambrian of China

Rare phosphatic tubular fossils from the Lower-Middle Cambrian Kaili Formation of Guizhou Province, southern China were originally identified as non-calcified algae or ‘worms’ (ScoleciellusLiu). Re-examination of these fossils indicates that specimens identified as non-calcified algae areSphenothallus taijiangensis n. sp., while specimens identified asScoleciellus belong toByronia natus (Liu).Sphenothallus taijiangensis andByronia natus from Lower Cambrian strata in the Kaili Formation are the oldest known representatives of their genera. In addition,B. natus (Liu) is the only known species ofByronia with the exception ofB. annulata Matthew (Middle Cambrian, British Columbia). CambrovitusMao et al., a tubular fossil from Middle Cambrian strata in the Kaili Formation, originally was classified as a hyolithid. However, the discovery of a nearly complete specimen possessing an apical attachment disk shows thatCambrovitus, likeByronia andSphenothallus, probably was a thecate cnidarian polyp.     

A revision of the Puerto Rican species of lepanthes (Orchidaceae)

Six species of the orchid speciesLepanthes are described as new. A seventh species,L. sanguined, previously known only from Jamaica, is reported from Puerto Rico. The current misspelling ofL. selenitepala, the only species of the genus previously reported from Puerto Rico, is corrected. A key to the eight Puerto Rican species ofLepanthes is presented, and the value of several interesting taxonomic characters is discussed. The possibility of apogamy in this genus is raised, and detailed biosystematic investigations are indicated as necessary for a complete understanding of the group.     

Comparative osteology of lotaks, Cyprinion kais and C. macrostomum (Cypriniformes, Cyprinidae), from Godarkhosh River, western Iran

Osteology of two cyprinid fishes, Cyprinion kais and C. macrostomum, from the Tigris-Euphrates basin was described and compared. Eight specimens of C. kais and ten specimens of C. macrostomum from Godarkhosh River (western Iran) were studied. The skeletal elements were prepared using clearing and softening methods and photographed. The differences between the two taxa include a deeper posterior position of the lower jaw with a much narrower labial surface, a longer last dorsal unbranched ray with weaker posterior serration, and a more embowed dentary, maxillary and premaxillary in C. kais. Based on these differences, the examined specimens of these two taxa could be easily distinguished.     

Hesperogavialis cruxenti N.Gen., N. SP., nouveau Gavialide (Crocodylia,Eusuchia) du Miocene superieur (Huayquerien) d'Urumaco (Venezuela)

A new gavialid from the Upper Miocene (“Huayquerian”) of Urumaco (western Venezuela) is described as Hesperogavialis cruxenti n. gen., n. sp. It is the only known South American gavialid in which, as in the Gavialidae from the Indian region, the nasals do not come into contact with the premaxillae. This ressemblance with the gavials of India is interpreted as a result of convergent evolution.     

A specialized new species of Ashicaulis (Osmundaceae,Filicales) from the Jurassic of Liaoning,NE China

A new species of structurally preserved fern rhizome, Ashicaulis plumites (Osmundaceae, Filicales), is described from the Middle Jurassic Tiaojishan Formation in western Liaoning Province, NE China. The new species is characterized by a peculiar sclerenchyma mass in the petiolar vascular bundle concavity. This sclerenchyma mass varies from a linear-shape to a mushroom-like shape with a remarkable outward protuberance, which distinguishes the present new species from other Ashicaulis species. Such a protuberance is very rare among osmundaceous ferns, and should represent a unique type for sclerenchymatous tissue in the osmundaceous vascular bundle concavity. Recognition of the peculiar structure of this new fossil species enriches anatomical diversity of permineralized osmundaceous ferns, indicating that the family Osmundaceae might have experienced a remarkable diversification during the Middle Jurassic in NE China. The new species show anatomical similarities to Osmunda pluma Miller from the Palaeocene of North America. The occurrence of A. plumites in the Middle Jurassic of China provides a new clue for understanding the evolution of some members of the living subgenus Osmunda.     

Pilot study of mold populations inside and outside of Puerto Rican residences

Puerto Rico has the highest asthma prevalence in the US. In the states, mold exposures have been linked to the development and exacerbation of asthma. For a pilot study of mold populations in Puerto Rico, dust and air samples were collected in January 2013 inside and outside of residences (n = 10) in the north eastern quadrant of Puerto Rico. Inside and outside (protected from rain) settled dust was collected by wiping above floor or ground-level surfaces with a Swiffer? duster cloth. Air samples were collected in five of the residences inside and five matching outside onto Malt Extract Agar and also onto G25N Agar. The dust (5 mg) was analyzed using mold-specific quantitative PCR and mold contamination estimated using the Environmental Relative Moldiness Index (ERMI) metric. Air sampled (150 l) plates were incubated and resulting mold colonies enumerated. The ERMI values were significantly (p = 0.03) greater inside the homes than outside, 20.37 versus 12.55, respectively. Aspergillus penicillioides, A. sydowii, Chaetomium globosum, the Eurotium group and Penicillium crustosum and A. ustus were found in significantly greater numbers inside than outside Puerto Rican residences based on the Wilcoxon rank sum test. However, after correction for multiple comparisons using the Holms–Bonferroni test, only the Eurotium group remained significantly greater. Air samples suggested higher culturable concentrations of molds outside but the differences were not significantly different. Although this is a small study, it suggests that some people in Puerto Rico are exposed to significantly higher mold concentrations indoors than outdoors.     

SPRING MIGRATION OVER PUERTO RICO AND THE WESTERN ATLANTIC, A RADAR STUDY

Migration over Puerto Rico was recorded by time-lapse filming of the display of a long-range surveillance radar on 40 days and 37 nights in the period 2 March-29 May 1971. Moderate density movements occurred every night; low density movements occurred on most days. Many birds, primarily passerines, took off from Puerto Rico each evening at 20–45 minutes after sunset.
Almost all birds flew to the west, NW or north. Birds were seen approaching from the direction of the Windward Islands and Venezuela, over Puerto Rico, and departing towards the Bahamas and eastern coast of the U.S. Uni- and multivariate analyses showed that the number of birds departing W-N each evening was positively correlated with following winds.
There is less night-to-night variation in the amount of migration at Puerto Rico than in eastern North America. However, this is apparently the result of less variable weather in the tropics, not the result of any lesser degree of meteorological selectivity by the migrants.
The tracks of the birds were correlated with wind direction. Birds moved WNW-NW with NE side winds but NW-NNW with SE following winds. The tracks were rarely exactly downwind. The variance amongst the directions of individual birds at any given time was usually small and not correlated with cloud cover or magnetic disturbances. The estimated headings of the birds varied from day to day in a pattern suggesting adjustment of headings to compensate at least partially for lateral wind drift.
In autumn many birds approach Puerto Rico from the north or even east of north; in spring few birds moved in the opposite directions. This difference in routes takes advantage of prevailing wind patterns.     

Dormancy, Turion Formation, and Germination by Different Clones of Spirodela polyrrhiza

Some clones of Spirodela polyrrhiza form dormant bodies called turions which require several weeks of chilling treatment before they proceed to renew growth and develop into vegetative fronds. The individual fronds of Spirodela are less than 5 mm long and can be grown aseptically in liquid culture. Turion formation and germination can serve as a bioassay for the various compounds involved in dormancy development.

Turion formation can be induced by manipulation of light intensity during the day, photoperiod, night temperature, day temperature, and concentration of nitrate in the culture medium. Different clones of Spirodela from northeastern United States, Puerto Rico, and Argentina had different requirements for turion formation. The clones from Argentina and Puerto Rico did not form turions under any of the experimental conditions imposed. Turions of some clones required chilling treatments for renewed vegetative growth while others did not. Both gibberellic acid and long photoperiods were required to bypass the chilling requirements of some clones, but not others.