Caribbean Species Research Articles

Differentiation in reproductive traits of geminate mangrove crabs of the genus Aratus (Decapoda: Brachyura) across the Central American Isthmus

AbstractThe mangrove crab Aratus pisonii was considered to have an amphi‐American distribution; however, a recent study revealed that the Eastern Tropical Pacific populations were genetically distinct, thus representing a new species: Aratus pacificus. These species separated by the Isthmus of Panama have diverged under different environmental conditions that may have influenced their reproductive biology. As the available information about this genus concerns almost exclusively the Caribbean species, the aim of the present study was to analyse and compare reproductive aspects of A. pacificus and A. pisonii obtained from both the Pacific and Caribbean coasts of Costa Rica. Females were collected from April 2011 to April 2012, and reproductive features such as breeding season, size distribution of ovigerous females, fecundity, reproductive output, embryo volume and embryo water content were assessed. Both species produced embryos during the entire sampled period. Most females of A. pacificus carrying embryos close to hatching were found during the rainy season. Ovigerous females of A. pisonii were substantially larger and reached sexual maturity at a larger size than females of A. pacificus. Embryo production started in A. pacificus at a smaller female size than in A. pisonii. As fecundity increased with female size, the average fecundity was lower in A. pacificus. Females of A. pisonii produced larger embryos, which might be related to lower food availability: higher energy content in the embryo enhances the chances of larval survival. These data regarding reproductive features of the Pacific and Caribbean species support the conclusion to separate A. pacificus from A. pisonii.

Chondrophycus anabeliae (Rhodomelaceae, Ceramiales), a new species in the Laurencia complex from the Mexican Caribbean

An ongoing phycological survey of the Laurencia complex in the Mexican Caribbean revealed an undescribed species belonging to Chondrophycus. The new species exhibits vegetative and reproductive structures typical of the genus, except for the presence of a slightly compressed thallus, a translucent outermost cortical cell layer with conspicuous cell wall projections, and tetrasporangia produced from a particular cell with the formation of one additional fertile periaxial cell. The phylogenetic position of this taxon was inferred based on chloroplast-encoded rbcL gene sequence analyses from 54 taxa and using three Rhodomelaceaen taxa as outgroups. The Mexican Caribbean species formed a monophyletic and fully supported clade within the Chondrophycus assemblage, but diverged at 5.8% from the most closely related taxon in the clade, whereas it diverged at 7.5% from the morphologically more closely related species C. dotyi from Kaneohe Bay, Oahu, Hawaiian Islands, indicating that the Mexican Caribbean species is morphologically and genetically distinct from other Chondrophycus species, and supporting its treatment as a new species.

Pseudoscorpion diversity and distribution in the West Indies: sequence data confirm single island endemism for some clades, but not others

The Caribbean Islands are a biodiversity hotspot harboring high levels of endemic biodiversity. In an effort to contribute to the characterization of invertebrate diversity in the region, we present an assessment of pseudoscorpion (Arachnida: Pseudoscorpiones) diversity and distribution with a focus on the superfamily Chthonioidea and the family Olpiidae. We used three markers (cytochrome c oxidase subunit I, histone H3 and 28S rRNA) to infer the first molecular phylogenies for each lineage and identified 32 putative new species in need of taxonomic assessment. These new records include the documentation of the genera Pseudochthonius Balzan, 1892 Lagynochthonius Beier, 1951, Tyrannochthonius Chamberlin, 1929 (Chthoniidae), Antillolpium Muchmore, 1991, Novohorus Hoff, 1945, and Pachyolpium Beier, 1931 (Olpiidae) on various islands. Chthonioid genera are strongly structured geographically, suggesting that many Caribbean species may be short-range endemics and excellent candidate systems for testing biogeographic hypotheses. The olpiid genus Pachyolpium is less geographically structured, which is consistent with the hypothesis that olpiids are better dispersers than chthonioids. This study aims to provide a foundation for taxonomic and biogeographic work on Caribbean pseudoscorpions, revealing a diversity that is far richer than is documented in the literature.

Cryptic Caribbean species of Scorpaena (Actinopterygii: Scorpaeniformes) suggested by cytogenetic and molecular data.

Cytogenetic and molecular analyses enabled identification of two cytotypes among individuals of the spotted scorpion fish Scorpaena plumieri from Margarita Island, Venezuela. Cytotype 1 was characterized by 48 subtelo-acrocentric chromosomes and fundamental number (number of chromosome arms; FN) equalled 48, while cytotype 2 was characterized by two metacentric and 46 subtelo-acrocentric chromosomes and FN was 50. These cytotypes also differed in the location of the ribosomal gene clusters and in the distribution of the constitutive heterochromatin. Moreover, fish from the cytotypes 1 and 2 were found to belong to distinct mitochondrial lineages. The presence of two S. plumieri cytotypes from two lineages separated by high genetic distance suggests that they correspond to sympatric cryptic species.

Rapid Extraction and Identification of Maitotoxin and Ciguatoxin-Like Toxins from Caribbean and Pacific Gambierdiscus Using a New Functional Bioassay

BackgroundCiguatera is a circumtropical disease produced by polyether sodium channel toxins (ciguatoxins) that enter the marine food chain and accumulate in otherwise edible fish. Ciguatoxins, as well as potent water-soluble polyethers known as maitotoxins, are produced by certain dinoflagellate species in the genus Gambierdiscus and Fukuyoa spp. in the Pacific but little is known of the potential of related Caribbean species to produce these toxins.MethodsWe established a simplified procedure for extracting polyether toxins from Gambierdiscus and Fukuyoa spp. based on the ciguatoxin rapid extraction method (CREM). Fractionated extracts from identified Pacific and Caribbean isolates were analysed using a functional bioassay that recorded intracellular calcium changes (Ca2+) in response to sample addition in SH-SY5Y cells. Maitotoxin directly elevated Ca2+i, while low levels of ciguatoxin-like toxins were detected using veratridine to enhance responses.ResultsWe identified significant maitotoxin production in 11 of 12 isolates analysed, with 6 of 12 producing at least two forms of maitotoxin. In contrast, only 2 Caribbean isolates produced detectable levels of ciguatoxin-like activity despite a detection limit of >30 pM. Significant strain-dependent differences in the levels and types of ciguatoxins and maitotoxins produced by the same Gambierdiscus spp. were also identified.ConclusionsThe ability to rapidly identify polyether toxins produced by Gambierdiscus spp. in culture has the potential to distinguish ciguatoxin-producing species prior to large-scale culture and in naturally occurring blooms of Gambierdiscus and Fukuyoa spp. Our results have implications for the evaluation of ciguatera risk associated with Gambierdiscus and related species.

A New Southern Caribbean Species of Angel Shark (Chondrichthyes, Squaliformes, Squatinidae), Including Phylogeny and Tempo of Diversification of American Species

A new species of Squatina, S. david, is described from the Colombian Caribbean. The new species differs from all the western North Atlantic angel sharks by lacking a mid-dorsal line of thorns or enlarged dermal denticles, by having an eye-spiracle distance larger than 1.5 times eye diameter, and each nasal flap with two rod-like barbels. Coloration is grayish to brownish yellow, males are dark-spotted, females have abundant whitish spots. Squatina david is nested within the American clade of angel sharks, being the sister species to the Brazilian species.

Calophyllum (Clusiaceae – Guttiferae) in Africa

Calophyllum africanum Cheek & Q. Luke is described and illustrated from Mali, in that part close to the Fouta Djalon of Guinea. Plant species present in its gallery forest habitat are listed in detail. Threatened by gold and uranium mining activities, C. africanum is here assessed as Critically Endangered according to the categories and criteria of IUCN. This is the first native Calophyllum known from continental Africa apart from the indo-pacific littoral C. inophyllum. The affinities of C. africanum appear to lie with the Neotropics and it is most similar to the Caribbean species C. antillanum.

MOLUSCOS DE LA REGION DE LA CIENAGA GRANDE DE SANTA MARTA (COSTA DEL CARIBE DE COLOMBIA)

This paper deals with the moDusk species known from the Ciénaga Grande de Santa Marta and from the littoral zone and the upper continental shelf of the coastal strip between lala de Salamanca and the balneario El Rodadero (Caribbean coast of Colombia, South America). 468 species and subspecies ofmarine, brackish-water and freshwater mollusks are reponed comprising 211 bivalves. 6 scaphopods and 251 gastropods. 101 species and 1 subspecies have been found in the Ciénaga Grande (most of them also in the sea), a further 9 marine species have been recorded only as old shells in the estuarine part of the Ciénaga Grande, the rest have been collected exclusively in the marine part of the investigated area. 268 species (120 bivalves, 3 scaphopods and 145 gastropods) have been live-collected, the remainder only as empty shells. 165 species and 9 subspecies (90 + 1 bivalves and 75 + 2 gastropods) are monographed and discussed in detail, among them 98 species and 1 subspecies (48 bivalves and 50 + 1 gastropods) from the Ciénaga Grande or its estuarine región, and 67 species and 2 subspecies only from the sea. Of the 98 species from the Ciénaga Grande, 64 have been live-collected, tlte oth*er 34 as empty shells only. The Ciénaga Grande de Santa Marta is the largest coastal lagoon of the Caribbean coast of Colombia, occupying an area of 450 km'. According to the season, drastic changes in salinity of between 0 and S0*/oo may be observed. Depth varies between 1 and 2.5 m, and the shore mostly consists of mangrove swamps. The bottom is muddy, some more or less extended areas having oyster reefs or shell concentrates. There are small areas in the northern part with sandy bottoms. Most mollusk species enter the lagoon and spread out within it as planktonic larvae by means of the currents, if conditions are favourable. Only very rarely are adult snails able to enter {he Ciénaga Grande actively. The propagation of the planktonic larvae within the lagoon depends on the nearest natural occurrence of the species, the duration of the pelagic phase, settlement depends on the presence of suitable substrate (besides the other ecological conditions needed). On account of finding older empty shells in a relative uniform state of preservation throughout the whole basin of the Ciénaga Grande, and of species not having been encountered there live, it can be assumed that there had previously existed an extremely long period of high salinity in the lagoon, with lower amplitudes than nowadays. According to C dates this period can be located ¿00-360 years ago, and its duration is estimated at at lea»t 3.5 years. The reason for this was most probably the greater interchange of sea and lagoonal water through several no longer existing, but still traceable, inlets. The zoogeographic division of those species treated in detail (except the freshwater species) is as follows: western Atlantic species. 68; Caribbean species. 48: southern Caibbean species, partly also from Brasil, 39. Í2 species are amphi-atlantic and 5 amphi-american. Six species known from Suriname, Venezuela or Brasil are recorded for the first time from Colombia and the southwestern Caribbean. 69 species have a win species (cognate species) existing in the Eastern Pacific (Panamic zoogeographic province). The portion of species with Pacific twin species found in the studied area is very high in comparison with other regions of the Caribbean, especially among the bivalves. This is due most probably to the similarity of the biotopes on large parts of the Colombian Caribbean coast and the tropical Eastern Pacific coast, preferred by these species.

LOS PECES GOBIIDAE DE LOS ARRECIFES DEL CARIBE COLOMBIANO. I. ESPECIES, DISTRIBUCION, FRECUENCIA Y ABUNDANCIA

Forty-six species of fishes of the family Gobiidae are reported from the reef environments (mainly coralline) of the Colombian Caribbean. Of these, 11 were previously unknown from the southern Caribbean and 24 are new records for the northern Colombian coast. Forty species occur in the continental coast and 37 in Isla de Providencia. Based on rotenone collections, information on their distribution, frequency and abundance is presented and analyzed. Among the small reef ichthyofauna, gobies are in average more than one fourth of the species, about one third of the individuals, and less than one tenth of thé biomass. The most common species in the whole Colombian Caribbean are Coryphopterus personatus and Gnatholepis thompsoni (present in 68% of the samples), followed by Quisqui/ius hipoliti (57%), Coryphopterus eidolon (52%) and Elacatinus illecebrosum (51%). Regional differences in composition, frequency and abundance of the reef gobiid fauna are noted. A key for the identification of the 17 studied genera is included.

COMENTARIOS PRELIMINARES SOBRE LOS CLINIDOS (TELEOS TEI: PERCIFORMES: CLINIDAE) DEL CARIBE COLOMBIANO

Included is a list of the 26 clinid species known from the Colombian Caribbean. Labrisomus sp., L. albigenys, L. bucciferus, Starksia atlantica, Acanthemblemaria rwasi, Coralliozetus sp., Ekemblemaria nigra, Emblemariopsis sp. and Enneanectes sp., are new reports from the northern Caribbean coast of South America. Malacoctenus macropus and Stathmonotus stahli (subespecies tekla) are new reports from the Colombian Caribbean. The richness of species of clinid fishes of the southern Caribbean is demostrated since there are 49 species known, of which 13 are supposed to be exclusive to this zone. This restricted zoogeographical distribution is clearly shown for the chaenopsids, since one fourth of the Caribbean species are known only from the south. The genera Ekemblemaria, Coralliozetus and Protemblemaria have been speciated principally in the American Pacific and in the Caribbean next to the Isthmus of Panama.

A minute ostracod (Crustacea: Cytheromatidae) from the Miocene Solimões Formation (western Amazonia, Brazil): evidence for marine incursions?

A huge wetland (the ‘Pebas system’) covered western Amazonia during the Miocene, hosting a highly diverse and endemic aquatic fauna. One of the most contentious issues concerns the existence, potential pathways and effects of marine incursions on this ecosystem. Palaeontological evidences (body fossils) are rare. The finding of a new, presumably marine ostracod species (Pellucistoma curupira sp. nov.) in the upper middle Miocene Solimões Formation initiated a taxonomic, ecological and biogeographical review of the genus Pellucistoma. We demonstrate that this marine (sublittoral, euhaline), subtropical–tropical taxon is biogeographically confined to the Americas. The biogeographical distribution of Pellucistoma largely depends on geographical, thermal and osmotic barriers (e.g. land bridges, deep and/or cold waters, sea currents, salinity). We assume an Oligocene/early Miocene, Caribbean origin for Pellucistoma and outline the dispersal of hitherto known species up to the Holocene. Pellucistoma curupira sp. nov. is dwarfed in comparison to all other species of this genus and extremely thin-shelled. This is probably related to poorly oxygenated waters and, in particular, to strongly reduced salinity. The associated ostracod fauna (dominated by the eurypotent Cyprideis and a few, also stunted ostracods of possibly marine ancestry) supports this claim. Geochemical analyses (δ18O, δ13C) on co-occurring ostracod valves (Cyprideis spp.) yielded very light values, indicative of a freshwater setting. These observations point to a successful adaptation of P. curupira sp. nov. to freshwater conditions and therefore do not signify the presence of marine water. Pellucistoma curupira sp. nov. shows closest affinities to Caribbean species. We hypothesize that Pellucistoma reached northern South America (Llanos Basin) during marine incursions in the early Miocene. While larger animals of marine origin (e.g. fishes, dolphins, manatees) migrated actively into the Pebas wetland via fluvial connections, small biota (e.g. P. curupira sp. nov.) were phoretically freighted and developed freshwater tolerance over long timescales.http://zoobank.org/urn:lsid:zoobank.org:pub:886C6476-393D-4323-8C0E-06BB8BD02FD9

A New Caribbean Species of <I>Helosis</I> (Balanophoraceae) with a Revised Key to the Genus

Abstract A new species, Helosis antillensis (Scybalioideae: Helosieae), is described, illustrated, and annotated. A key of the known species of Helosis is presented. The new species is the third recognized within the genus and the second Helosis species in the Neotropics. It is also the second Balanophoraceae endemic to the islands of the Caribbean Sea. The new species, related to H. cayennensis, is distinguished by runners with remarkable verrucous surface projections, an inflorescence stalk up to 4.5 cm long, volva that are medially to apically inserted, peltate bracts with distinctly apiculate apices, staminate flowers with free filaments, and pistillate flowers with bifid and deltoid perianth segments (0.3–0.4 mm long).

Ascidians from Rocas Atoll, northeast Brazil

Rocas Atoll is the only one of its kind in the South Atlantic—and the first Brazilian marine biological reserve. This is the first report about the ascidians from Rocas. A total of 12 species were found, 5 of them not hitherto described: Ascidia viridina sp. nov., Didemnum rochai sp. nov., Leptoclinides crocotulus sp. nov., Polysyncraton maurizeliae sp. nov., and Trididemnum rocasensis sp. nov.). One Caribbean species, Didemnum halimedae, was also discovered in the region for the first time. Further, this is the first record of Didemnum digestum in the Atlantic. The results indicate a high degree of endemism in the ascidian fauna from Rocas Atoll, where didemnids are presently the most important members.

The influence of spawning periodicity on population connectivity

Many coral reef populations exist as discrete habitat patches linked through larval dispersal into a larger network. On these reefs, organisms spawn periodically and release propagules over a range of frequencies. Biophysical models of larval transport examine marine networks, yet particle release frequency needs careful consideration. We describe the time between sequential spawning events as the release interval and define any linkage of modeled larvae between two habitat sites as a connection. We investigate how changing the release interval affects the connectivity networks of three Caribbean species with low- to high-dispersal potential and swimming behavior. We find that spawning periodicity controls the number and persistence of network connections. Further, larval vertical movement behavior stabilizes the network, significantly increasing connections and connection persistence. This work demonstrates the impact of release interval on connectivity networks and underscores including larval behavior with realistic spawning periodicity in biophysical models of larval transport.

Molecular evidence for an old world origin of Galapagos and Caribbean band-winged grasshoppers (Acrididae: Oedipodinae: Sphingonotus).

Patterns of colonization and diversification on islands provide valuable insights into evolutionary processes. Due to their unique geographic position and well known history, the Galapagos Islands are an important model system for evolutionary studies. Here we investigate the evolutionary history of a winged grasshopper genus to infer its origin and pattern of colonization in the Galapagos archipelago. The grasshopper genus Sphingonotus has radiated extensively in the Palaearctic and many species are endemic to islands. In the New World, the genus is largely replaced by the genus Trimerotropis. Oddly, in the Caribbean and on the Galapagos archipelago, two species of Sphingonotus are found, which has led to the suggestion that these might be the result of anthropogenic translocations from Europe. Here, we test this hypothesis using mitochondrial and nuclear DNA sequences from a broad sample of Sphingonotini and Trimerotropini species from the Old World and New World. The genetic data show two distinct genetic clusters representing the New World Trimerotropini and the Old World Sphingonotini. However, the Sphingonotus species from Galapagos and the Caribbean split basally within the Old World Sphingonotini lineage. The Galapagos and Caribbean species appear to be related to Old World taxa, but are not the result of recent anthropogenic translocations as revealed by divergence time estimates. Distinct genetic lineages occur on the four investigated Galapagos Islands, with deep splits among them compared to their relatives from the Palaearctic. A scenario of a past wider distribution of Sphingonotus in the New World with subsequent extinction on the mainland and replacement by Trimerotropis might explain the disjunct distribution.

Discordance between morphological and molecular species boundaries among Caribbean species of the reef sponge Callyspongia.

Sponges are among the most species-rich and ecologically important taxa on coral reefs, yet documenting their diversity is difficult due to the simplicity and plasticity of their morphological characters. Genetic attempts to identify species are hampered by the slow rate of mitochondrial sequence evolution characteristic of sponges and some other basal metazoans. Here we determine species boundaries of the Caribbean coral reef sponge genus Callyspongia using a multilocus, model-based approach. Based on sequence data from one mitochondrial (COI), one ribosomal (28S), and two single-copy nuclear protein-coding genes, we found evolutionarily distinct lineages were not concordant with current species designations in Callyspongia. While C. fallax,C. tenerrima, and C. plicifera were reciprocally monophyletic, four taxa with different morphologies (C. armigera,C. longissima,C. eschrichtii, and C. vaginalis) formed a monophyletic group and genetic distances among these taxa overlapped distances within them. A model-based method of species delimitation supported collapsing these four into a single evolutionary lineage. Variation in spicule size among these four taxa was partitioned geographically, not by current species designations, indicating that in Callyspongia, these key taxonomic characters are poor indicators of genetic differentiation. Taken together, our results suggest a complex relationship between morphology and species boundaries in sponges.

Inter- and Intra-specific variation in egg size among reef fishes across the Isthmus of Panama

Effects of planktonic food supplies and temperature on pelagic fish larvae are thought to be the primary environmental determinants of adaptive variation in egg size. Differences between the Atlantic and Pacific coasts of Panama in primary production (higher in the Pacific due to upwelling) and temperature (less seasonal in the non-upwelling Caribbean) allow testing such ideas. We compared the volumes, dry weights and energy content of eggs of 24 species of reef fishes from the two sides of the isthmus during the cool and warm seasons. Both egg volume and egg dry weight were good predictors of egg energy content among species, although not within species. Caribbean species produced larger eggs than their close relatives in the Pacific. In the Pacific, eggs were significantly larger during the cool upwelling season than during the warm, non-upwelling period, with a similar but weaker seasonal pattern evident in the Caribbean. The production of larger eggs in the low-productivity Caribbean is consistent with the hypothesis that species produce larger eggs and offspring when larval food supplies are lower. Parallel patterns of seasonal variation in eggs size and the greater strength of that relationship in the Pacific indicate that temperature drives seasonal variation in egg size within species. The decline in egg size with increasing temperature, a general pattern among ectotherms, may be a physiological side-effect, due to differing effects of temperature on various metabolic processes during oogenesis or on hormones that influence growth and reproduction. Alternatively, the seasonal pattern may be adaptive in these fishes, by affecting larval performance or maintaining a particular timeline of major events during embryonic development.

Trait-mediated ecosystem impacts: how morphology and size affect pumping rates of the Caribbean giant barrel sponge

Sponges are a dominant component of Caribbean coral reef suspension-feeding communi- ties. Understanding how pumping rates are affected by sponge size and morphology, as well as the en - vironment, is fundamental to understanding the ecological interactions that are mediated by sponge filtration. In a comprehensive in situ investigation of sponge pumping, the excurrent seawater velocities of 274 specimens of the largest Caribbean species, the giant barrel sponge Xestospongia muta, were measured at sites in the Bahamas and Florida Keys to investigate (1) the relationship between excurrent velocity distributions and sponge morphology, (2) the scaling relationship between pumping and sponge size, and (3) temporal variation of pumping and sensitivity to environmental changes. Excurrent velocity distributions across the osculum showed peak velocities at the center and diminishing veloci- ties near the edges of the osculum. The degree of center-weighting was explained by the distribution of sponge biomass relative to the spongocoel. Volu- metric pumping rates scaled isometrically with sponge size and averaged 0.06 ± 0.04 l s −1 l −1 sponge tissue, but were reduced for extremely large sponges. Pumping activity was relatively constant over short temporal scales, but varied over longer scales; how- ever, variations in pumping rates, in cluding periods of cessation, were asynchronous across the pop - ulation and uncorrelated with changes in environ- mental conditions. We estimate that populations of X. muta in the Florida Keys and Bahamas process a volume of water equivalent to a layer 1.7 to 12.9 m thick each day and overturn the water column every 2.3 to 18.0 d.

A new species of Cyphomyia Wiedemann from the Dominican Republic with a key to Caribbean species of the genus (Diptera, Stratiomyidae, Clitellariinae).

A new species of Cyphomyia Wiedemann, Cyphomyia baoruco sp. n., is described from the Dominican Republic. A key to the species of Cyphomyia known from the Caribbean islands is provided.

Phylogeny of Genus Cupuladria (Bryozoa, Cheilostomata) in the Neogene of Tropical America

We used 57 morphometric characters to discriminate 17 extant and fossil Cupuladria species and analyzed their phylogenetic relationships in relation to extant Discoporella species. Data were gathered from 496 extant and fossil Cupuladria specimens ranging in age from early Miocene to Recent and distributed from the Caribbean to tropical eastern Pacific. A first series of discriminant analyses distinguished three morphological groups: Cupuladria with vicarious avicularia, Cupuladria without vicarious avicularia, and Discoporella. Further discriminant analyses identified 17 species of Cupuladria. Cladistic analyses of these three groups yielded four equally parsimonious trees. All of the consensus trees exhibited the same topology, dividing the 25 tropical American cupuladriids into four distinct monophyletic clades, including Discoporella, and are consistent with previous molecular phylogenies except that there are no molecular data for the CV2 clade. Diversification of species was higher in the CV1 and CV2 clades than CNV clade, and involved mostly Caribbean species. Cupuladria with vicarious clade 1 (CV1) includes: C. monotrema, C. pacificiensis, C. exfragminis, C. cheethami, C. biporosa, and four new species: C. pervagata, C. floridensis, C. colonensis and C. dominicana. Cupuladria with vicarious clade 2 (CV2) includes: C. multesima, C. incognita, and three new species C. collyrida, C. veracruxiensis and C. planissima. Cupuladria clade without vicarious (CNV) includes: C. surinamensis, C. panamensis, and one new species C. gigas. The stratigraphic occurrence of species is consistent with cladogram topology within clades. However hypothesized cladistic relations among clades are the reverse of their stratigraphic occurrence with younger clade CNV appearing as the hypothetical ancestor of the two older clades CV1 and CV2. More extensive collections of early to middle Miocene specimens of Cupuladria and Discoporella will be required to resolve this apparent paradox.