An Oplegnathid beak (Osteichthyes: Perciformes) from the Early Miocene of Patagonia. Extirpation of several vertebrates from southern Atlantic Ocean

The first record of the knifejaw family Oplegnathidae in the Atlantic Ocean and in South America is reported. It comes from the early Miocene Gaiman Formation lowermost beds at the lower Río Chubut valley, central-eastern Patagonia. Family Oplegnathidae does not occur in the Atlantic today, but it was widespread in comparison to other knifejaw fishes such as scarids and odacids. Several aquatic vertebrates were extirpated from the southern Atlantic Ocean in the late Neogene. This record establishes a minimal age (early Miocene) for the extirpation of the family Oplegnathidae in the Atlantic Ocean.     

Miocene bristlemouths (Teleostei: Stomiiformes: Gonostomatidae) from the Makrilia Formation,Ierapetra, Crete

Bristlemouths of the genus Cyclothone are currently regarded as the most abundant vertebrates on Earth. The fossil record seems to suggest that these fishes diversified during the Miocene in the Pacific Ocean, but there is no evidence of their presence in the Miocene of the Atlantic Ocean and Mediterranean basin. A new bristlemouth, Cyclothone gaudanti sp. nov. (Teleostei, Stomiiformes, Gonostomatidae), is described herein based on 16 specimens from the Upper Miocene Makrilia Formation (late Tortonian of Crete, Greece). The small sized species is characterized by light pigmentation, 30–31 (14–15 + 15–16) vertebrae, dorsal fin with 10–13 rays, anal fin with 10–14 rays, premaxilla bearing seven closely spaced teeth, maxilla with 42–55 teeth, epipleurals, and autogenous parhypural. The presence of epipleurals appears to be unique of this Miocene species, and the re-establishment of this ancestral character state may be possibly interpreted as related to a phylogenetic character reversal. Morphological and paleoecological considerations suggest that this species possibly inhabited the upper mesopelagic layer, at depths ranging from 2–300 and 500 meters.     

Are characiform Fishes Gondwanan in Origin? Insights from a Time-Scaled Molecular Phylogeny of the Citharinoidei (Ostariophysi: Characiformes)

Fishes of the order Characiformes are a diverse and economically important teleost clade whose extant members are found exclusively in African and Neotropical freshwaters. Although their transatlantic distribution has been primarily attributed to the Early Cretaceous fragmentation of western Gondwana, vicariance has not been tested with temporal information beyond that contained in their fragmentary fossil record and a recent time-scaled phylogeny focused on the African family Alestidae. Because members of the suborder Citharinoidei constitute the sister lineage to the entire remaining Afro-Neotropical characiform radiation, we inferred a time-calibrated molecular phylogeny of citharinoids using a popular Bayesian approach to molecular dating in order to assess the adequacy of current vicariance hypotheses and shed light on the early biogeographic history of characiform fishes. Given that the only comprehensive phylogenetic treatment of the Citharinoidei has been a morphology-based analysis published over three decades ago, the present study also provided an opportunity to further investigate citharinoid relationships and update the evolutionary framework that has laid the foundations for the current classification of the group. The inferred chronogram is robust to changes in calibration priors and suggests that the origins of citharinoids date back to the Turonian (ca 90 Ma) of the Late Cretaceous. Most modern citharinoid genera, however, appear to have originated and diversified much more recently, mainly during the Miocene. By reconciling molecular-clock- with fossil-based estimates for the origins of the Characiformes, our results provide further support for the hypothesis that attributes the disjunct distribution of the order to the opening of the South Atlantic Ocean. The striking overlap in tempo of diversification and biogeographic patterns between citharinoids and the African-endemic family Alestidae suggests that their evolutionary histories could have been strongly and similarly influenced by Miocene geotectonic events that modified the landscape and produced the drainage pattern of Central Africa seen today.     

New fossil record of Lactoridaceae in southern South America: a palaeobiogeographical approach

Lactoridaceae are a monotypic family confined to Masatierra Island, Juan Fernández Archipelago, in the Pacific Ocean. It grows in the understorey of a subtropical montane rain forest. Lactoridaceae most probably originated in southern South Africa in the Cretaceous, with the oldest records in the Turonian–Campanian, and reached its widest palaeogeographical distribution by the Maastrichtian, extending into Australia, India, Antarctica, and North and South America. In this paper, we report a new fossil find of lactoridaceous tetrads from the early Miocene of eastern Patagonia, southern South America. This record is the youngest and geographically one of the closest to the extant Lactoris distribution area. Patagonian fossil material shows greater similarities to extant L. fernandeziana Phil. than to any other described morphotaxon. The family may have migrated into South America, either via Africa (through the Atlantic Ocean) or Antarctica, by the Maastrichtian, growing in eastern Patagonia up to the early Miocene. Arid conditions established in this region by the middle–late Miocene onwards would have determined the restriction of forests to the western lands. Lactoridaceae may have followed a similar migration pattern towards the Pacific coast of South America. The shifting of Lactoridaceae towards Masatierra Island would have occurred in the last 4 Myr by long‐distance dispersal events (perhaps by birds). © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 158 , 41–50.     

Neogene history of Sporolithon Heydrich (Corallinales,Rhodophyta) in the Mediterranean region

Most modern species of Sporolithon live in tropical and subtropical areas and only one species of the genus, S. ptychoides, occurs in the Mediterranean Sea. The scarce present-day populations of Sporolithon in the Mediterranean region are relics of a long history of the genus in this area since the Early Cretaceous. Analysis of data from the palaeontological literature, combined with the study of both fossil samples and Recent ones collected from Italy and Spain, shows that during the Miocene variations in the number of Sporolithon species in the Mediterranean region parallel changes in global temperature. After a maximum species richness in the Langhian (early Mid Miocene), coincident with the Miocene climatic optimum, the number of species decreased to just two before the Messinian Salinity Crisis. This marked decline follows the global cooling event that began at around 14 Ma. The closure of the connections of the Mediterranean region with the Indian Ocean during the Langhian left Mediterranean Sporolithon populations isolated from the main dispersal area of the genus. After the Messinian desiccation, a single species, S. ptychoides, re-invaded the Mediterranean Basin during the Early Pliocene and continues to inhabit this temperate sea today. The Atlantic Ocean is the most probable source of the re-invading Sporolithon plants.     

Ancient Divergence in the Trans-Oceanic Deep-Sea Shark Centroscymnus crepidater

Unravelling the genetic structure and phylogeographic patterns of deep-sea sharks is particularly challenging given the inherent difficulty in obtaining samples. The deep-sea shark Centroscymnus crepidater is a medium-sized benthopelagic species that exhibits a circumglobal distribution occurring both in the Atlantic and Indo-Pacific Oceans. Contrary to the wealth of phylogeographic studies focused on coastal sharks, the genetic structure of bathyal species remains largely unexplored. We used a fragment of the mitochondrial DNA control region, and microsatellite data, to examine genetic structure in C. crepidater collected from the Atlantic Ocean, Tasman Sea, and southern Pacific Ocean (Chatham Rise). Two deeply divergent (3.1%) mtDNA clades were recovered, with one clade including both Atlantic and Pacific specimens, and the other composed of Atlantic samples with a single specimen from the Pacific (Chatham Rise). Bayesian analyses estimated this splitting in the Miocene at about 15 million years ago. The ancestral C. crepidater lineage was probably widely distributed in the Atlantic and Indo-Pacific Oceans. The oceanic cooling observed during the Miocene due to an Antarctic glaciation and the Tethys closure caused changes in environmental conditions that presumably restricted gene flow between basins. Fluctuations in food resources in the Southern Ocean might have promoted the dispersal of C. crepidater throughout the northern Atlantic where habitat conditions were more suitable during the Miocene. The significant genetic structure revealed by microsatellite data suggests the existence of present-day barriers to gene flow between the Atlantic and Pacific populations most likely due to the influence of the Agulhas Current retroflection on prey movements.     

Davallia (Polypodiales: Davalliaceae) macrofossils from Early Miocene Otago (New Zealand) with in situ spores

Fossil fern fronds referable to the extant fern genus Davallia (Polypodiales: Davalliaceae) bearing sporangia with in situ spores are described from the Early Miocene Foulden Maar diatomite deposit, Otago, New Zealand. The fronds are the first published Southern Hemisphere macrofossil record for the family and provide valuable palaeoclimate data supporting warm conditions in Early Miocene New Zealand. The matching of Davallia fronds to the form spore taxon Polypodiisporites radiatus shows that the genus has had a long, apparently continuous history throughout late Cenozoic New Zealand.     

THE EARLIEST SIRENIAN (MAMMALIA: DUGONGIDAE) FROM THE EASTERN PACIFIC OCEAN

The partial skull and mandible of an unidentified halitheriine dugongid, collected from the Early Miocene Nye Mudstone in Lincoln County, Oregon, USA, is the earliest record of the Sirenia in the eastern Pacific Ocean. It is probably earlier than Early or Middle Miocene sirenians recently found in Peru, and is definitely earlier than any known from California or Baja California. However, it appears to be slightly younger than fossil sirenian remains recently reported from Late Oligocene rocks in Japan. The Oregon specimen is also the most northern record of the Sirenia on the west coast of North America prior to the Pleistocene although other sirenians did evidently reach and surpass such latitudes by the Late Miocene when a dispersal took place from America to the North Pacific coasts of the Old World. The Oregon specimen probably represents sirenians that spread to the North Pacific from the Caribbean, quite possibly prior to the Miocene. The Nye Mudstone was deposited during the warmest period of the Neogene on the coast of Oregon, and it does not seem necessary to postulate a greater degree of cold-tolerance for the Oregon sirenian than is exhibited by living sea cows.     

Upper Eocene to Middle Miocene ostracode faunas and paleo-oceanography of the North Coastal Belt,Jamaica, West Indies

The ostracode fauna of the Montpelier Group (Upper Eocene-Middle Miocene) exposed in the western part of the North Coastal Belt of Jamaica contains representatives of three paleo-environments. Allochthonous shelf and littoral species, characterized by abraded carapaces and eye tubercles, and a diverse group of archibenthal (slope) forms are present throughout. Species restricted to the World Ocean Psychrosphere (> 1000 m), notably Bradleya dictyon, Australoecia tipica, Agrenocythere hazelae and Macrocypris spp., first occur in sediments of earliest Miocene age (planktonic foraminiferal zone N4). Their presence establishes a minimum age for the entry into the Cayman Trench of frigid (<8–10°C) water masses drawn from the Atlantic thermohaline stratification.Upper Eocene and Oligocene assemblages are dominated by smooth, blind genera such as Krithe, Messinella and Bythocypris and lived in lower thermospheric conditions (10°C) at or near the base of the thermocline (700– 900 m). During the Early Miocene, downfaulting of the north island slope of Jamaica in response to southward tilting of the Nicaraguan Rise brought the Montpelier depositional site into contact with progressively deeper and colder water-masses. This subsidence culminated in the late Early Miocene; faunas of this age contain large numbers of Bradleya dictyon, Agrenocythere hazelae, Macrocypris sp. 1, Bairdia oarion and Bairdoppilata cassida. They suggest paleodepths of 1500–2000 m and the local presence of a 3–4° water-mass tentatively identified as the North Atlantic deep water. If this interpretation is correct, then the maximum sill-depth and water-mass configuration of the Miocene Cayman Trench have persisted to the present. Middle Miocene assemblages indicate a return to paleodepths of 1000–1500 m heralding the pronounced Upper Miocene to mid-Pleistocene tectonism which elevated Montpelier strata above sea level. An alternative view attributes the Miocene ostracode succession in the Montpelier to episodes in the development of the Atlantic circulation as recognized in the northeast Atlantic.Montpelier deposition took place either on a broad step intervening between the northern edge of the Clarendon Platform and the abyssal basins of the Cayman Trench or on a Tertiary analog of the existing north island slope. These results have emphasized the value of detailed taxonomic and morphologic studies of deep-sea ostracodes in geohistorical reconstruction.     

A new record of Gobius jarosi (Teleostei,Gobiidae) from the Early Miocene of Poland with inference to paleogeography and palaeoecology of the Carpathian Basin

Abstract

Gobies (family Gobiidae) were in the past and now important components of marine ecosystems as an essential part of the food chain. However, the early fossil record of this group is relatively meager, with only scarce skeletal remains. The oldest known representative of the genus Gobius has been recently described from the Early Miocene of Czech Republic as Gobius jarosi P?ikryl & Reichenbacher, 2018. Here we present a detailed study of a well-preserved goby skeleton of the same age from the Harta locality (Poland). This specimen is assumed as belonging to Gobius jarosi based on its almost complete morphological and meristic identity with the type material from the Vá?any nad Litavou locality. Some aspects of the paleogeography and paleoecology of the Early Miocene fish assemblage from Harta with special reference to the Carpathian Basin are also discussed in this paper.     

Cenozoic radiolarian paleobiogeography: Implications concerning plate tectonics and climatic cycles

A preliminary study of the paleobiogeographic patterns of radiolarian facies during the Paleogene and subsequent time shows that:(1) Through time radiolarian assemblages display distinct faunal provincialism reminiscent of modern faunal distributions correlated with planetary temperature gradients and surface oceanic conditions. The equatorial—tropical radiolarian fauna extended apparently unrestricted across the Pacific Ocean, the Caribbean Sea and the Atlantic Ocean through Early Miocene time. In the Caribbean Sea and the Atlantic Ocean, radiolarians reached their maximum abundance in the Eocene and Oligocene. Subsequently, they gradually declined to virtual disappearance in these areas in the early Miocene. Their Pacific counterparts remained practically undisturbed, except that post early Miocene assemblages there showed a marked trend toward decreasing test thickness. This trend has since been a worldwide characteristic of Neogene radiolarian assemblages and their modern equivalents. It is postulated that the disappearance of radiolarians in the Carribean Sea and the Atlantic Ocean at the end of the Paleogene is related to the onset of the emergence of the isthmus of Panama which interrupted the preexisting oceanic circulation between the Pacific and Atlantic Oceans.(2) Throughout the Paleogene there have been marked sequential fluctuations in the radiolarian assemblages of the Caribbean Sea which indicate intermittent incursions of higher-latitude fauna in this area. Associated with the faunal fluctuations are cyclic variations in the total carbonate of the sediment with patterns also comparable in duration to Pleistocene carbonate cycles in the equatorial Pacific known to have been induced by climatic changes. Based on similarities with Pleistocene climatic cycles in the equatorial Pacific and elsewhere, it is surmised that the faunal and lithologic fluctuations observed in Paleogene radiolarian sediments were also induced by the biologic and physico-chemical processes associated with worldwide changes in the climatic conditions of that time.     

DNA evidence for a Paleocene origin of the Alcidae (Aves: Charadriiformes) in the Pacific and multiple dispersals across northern oceans

The Alcidae is a group of marine, wing-propelled diving birds known as auks that are distributed along the coasts of the northern oceans. It has been suggested that auks originated in the Pacific coastal shores as early as the Miocene, and dispersed to the Atlantic either through the Arctic coasts of Eurasia and North America (northern dispersal route), or through upwelling zones in the coastal areas of California to Florida (southern dispersal route), before the closure of the Isthmus of Panama in the Pliocene. These hypotheses have not been tested formally because proposed phylogenies failed to recover fully bifurcating, well-supported phylogenetic relationships among and within genera. We therefore constructed a large data set of mitochondrial and nuclear DNA sequences for 21 of the 23 species of extant auks. We also included sequences from two other extant and one extinct species retrieved from GenBank. Our analyses recovered a well-supported phylogenetic hypothesis among and within genera. Aethia is the only genus for which we could not obtain strong support for species relationships, probably due to incomplete lineage sorting. By applying a Bayesian method of molecular dating that allows for rate variation across lineages and genes, we showed that auks became an independent lineage in the Early Paleocene and radiated gradually from the Early Eocene to the Quaternary. Reconstruction of ancestral areas strongly suggests that auks originated in the Pacific during the Paleocene. The southern dispersal route seems to have favored the subsequent colonization of the northern Atlantic Ocean during the Eocene and Oligocene. The northern route across the Arctic Ocean was probably only used more recently after the opening of the Norwegian Sea in the Middle Miocene and the opening of the Bering Strait in the Late Miocene. We postulate that the ancestors of auks lived in a warmer world than that currently occupied by auks, and became gradually adapted to feeding in cool marine currents with high biomass productivity. Hence, warmer tropical waters are now a barrier for the dispersal of auks into the Southern Hemisphere, as it is for penguins in the opposite direction.     

New data on Lepidion schmidti (Gadiformes: Moridae) from the north-east Atlantic Ocean

A new record of Lepidion schmidti (Gadiformes: Moridae) is reported from the Bay of Biscay (north-east Atlantic Ocean). Lepidion schmidti is a rare and poorly known species, scarcely described in the ichthyological literature. Morphometric and meristic characteristics of the specimen are given. A compilation of the specimens caught in the north-east Atlantic Ocean was carried out and the current status of the species in Atlantic waters is discussed. Lepidion schmidti is characterized mainly by the presence of an inverted V-shaped patch of vomerine teeth and a V-shaped crest on the dorsal surface of the head with the apex anterior. The presence of supernumerary anal fin rays in this species is described for the first time. The results obtained confirm the presence of L. schmidti from the north-east Atlantic Ocean.     

Molecular phylogeny of the spiny lobster genus Palinurus (Decapoda: Palinuridae) with hypotheses on speciation in the NE Atlantic/Mediterranean and SW Indian Ocean

Sequence data derived from the mitochondrial DNA 16S rRNA and COI genes were used to determine the phylogenetic relationships among six Palinurus spiny lobster species. Three species (P. charlestoni, P. elephas, and P. mauritanicus) occur in the northeastern Atlantic/Mediterranean, and the others (P. barbarae, P. delagoae and P. gilchristi) inhabit the southwestern Indian Ocean. Parsimony and model based phylogenetics strongly supported the monophyly of the genus. A combined parsimony analysis based on 1001bp and 274 parsimony informative characters recovered the most resolved phylogeny with >70% bootstrap support for associations among species. The Atlantic P. charlestoni consistently clusters nested within the Indian Ocean clade, and the mtDNA sequence divergence between the two most distant species is 8.24%. If the northward collision of Africa with Eurasia in the Miocene caused the final physical separation between the Atlantic and Indian Ocean taxa, then the Palinurus mtDNA (COI and 16S combined) evolved no faster than 0.18% (lower bound) to 0.36% (upper bound) per lineage per million years. The six extant species occur in the pathways of the North Atlantic and South Indian Ocean gyres, and hypotheses on their radiation are developed relative to the strengthening of boundary currents in the Miocene and life history traits congruent with survival in strong ocean currents.     

Pleistocene camelids from the Syrian Desert: The diversity in El Kowm

The family Camelidae has been present in Eurasia since the latest Miocene, and several species are recognized, but their evolution is poorly known. The region of El Kowm, central Syria, includes several sites spanning the Early to Late Pleistocene and provides the only abundant fossil record of camelids in the Middle East. Our preliminary results show that several species are present over the sequence, revealing some surprising evolutionary trends.     

The beginnings of the Sargasso assemblage in the Tethys?

An assemblage of organisms, here termed “quasi-Sargasso”, occurs in the Oligocene menilite beds of the Carpathian flysch. It is suggested that this assemblage migrated into the Atlantic Ocean, probably during the Miocene. Its further evolution, which gave rise to the present-day Sargasso assemblage, took place in the middle Atlantic area.     

A new species of parasitic copepod,Shiinoa bakeri (Shiinoidae), with a new host record for Shiinoa elagata Cressey

Summary A new species of Shiinoa parasitic on the nasal lamellae of Indian Ocean and western Atlantic lutjanid fishes is described. A new record of Shiinoa elagata, originally described from Pacific Elagatus bipinnulatus, is reported from western Atlantic Sphyraena barracuda from Belize. The new species described herein brings the total number of Shiinoa species described to four. The family Shiinoidae is redefined.     

First discovery of the Miocene northern Atlantic sperm whale Orycterocetus in the Mediterranean

An incomplete mandible of a fossil sperm whale (Odontoceti; Physeteridae) is described. It is a portion of elongated and narrow symphysis with cylindrical and slightly curved teeth without enamel. The specimen, collected from the Miocene “Pietra leccese” sediments of South Italy, appears to represent a species of Orycterocetus, and is the first such record from the Mediterranean. Considering the wide diffusion of Orycterocetus in the North Atlantic, we believe its rare presence in the Mediterranean as occasional and due to a certain degree of interchange between the Mediterranean and the North Atlantic cetacean fauna during the Miocene.     

Morphological and molecular study of <Emphasis Type="Italic">Longicollum pagrosomi</Emphasis> Yamaguti, 1935 (Acanthocephala: Pomphorhynchidae) from the barred knifejaw <Emphasis Type="Italic">Oplegnathus fasciatus</Emphasis> (Temminck &amp; Schlegel) (Perciformes: Oplegnathidae) in the East China Sea

Longicollum pagrosomi Yamaguti, 1935 (Acanthocephala: Pomphorhynchidae) collected from the barred knifejaw Oplegnathus fasciatus (Temminck & Schlegel) (Perciformes: Oplegnathidae) in the East China Sea (off Zhoushan Islands) was studied using light and scanning electron microscopy. The SEM observations revealed for the first time the presence of about 28 well-developed sensory papillae arranged in a circle on the copulatory bursa. In addition, L. pagrosomi was characterised using molecular methods by sequencing of the internal transcribed spacer (ITS) of the ribosomal DNA based on the newly collected material. Longicollum pagrosomi is the first species of the genus with the ITS region sequenced for the purpose of species identification. These new morphological and molecular data contributed to a reliable and accurate specific identification and differentiation of species.