Ainara Badiola

Amphibians and reptiles from the Early Miocene of the Bardenas Reales of Navarre (Ebro Basin, Iberian Peninsula)

The Lower Miocene deposits of the Bardenas Reales of Navarre (NW Ebro Basin, northern Iberian Peninsula) have yielded a diverse vertebrate fauna, including remains of amphibians and reptiles. These remains occur in several localities in the Tudela Formation. The fossiliferous levels belong to the Biozones MN2b-3 (Biozones Z-A of the Ramblian, i.e., Late Aquitanian to Early Burdigalian in age). The amphibians and reptiles represent at least 13 out of 37 vertebrate species. Amphibians consist of a salamandrid urodele and two or three anurans. All the turtles are cryptodirans and consist of the chelydrid Chelydropsis apellanizi, the testudinids Ptychogaster (Temnoclemmys) bardenensis and Ptychogaster ronheimensis, and a Trionychinae indet. Squamates are represented by the anguid lizard Ophisaurus sp., a non-anguid lacertilian, an amphisbaenian, the erycine boid? Eryx sp., and indeterminate colubrids. Crocodilian remains are assigned to the basal alligatoroid Diplocynodon sp. The fossil associations of the Bardenas Reales of Navarre suggest that the vertebrates lived in the centre of an endoreic basin with stretches of water under intertropical to subtropical climatic conditions.

New Endemic Eocene Equoids from the Iberian Peninsula (Western Europe)

Abstract A new plagiolophine equoid from the Eocene of the Iberian Peninsula, Iberolophus gen. nov., is herein reported. This new genus includes two species: I. arabensis sp. nov. (type species) from the Late Eocene (Headonian) of Zambrana (Araba, Basque Country) and I. jimenezi sp. nov. from the late Middle Eocene (Robiacian) of Mazaterón (Soria, Castilla y León). Iberolophus exhibits an unusual dental pattern that has not yet been reported in any other perissodactyl or ungulate to date. A complete (with P1/p1) and very long non-lophoid premolar series, in which premolars exhibit one (in the earlier members) or two (in the later members) high and pointed cusp(s) anteriorly and a low and long backward extended talon/talonid posteriorly, with a bumpy surface texture, is combined with a typical plagiolophine type lophodont and heterodont molar series. The new taxa are ranked as members of the endemic fauna of the Western Iberian Bioprovince. The latter includes the Eocene sites of the central and western Iberian basins (Duero, Almazán, Oviedo, and Miranda-Trebiño Basins), which have yielded Middle and Late Eocene mammal fossil assemblages (mainly perissodactyls, rodents and primates) which differ from those of the Southern Pyrenean Basins and the rest of Europe. The endemism of the perissodactyl faunas persisted during the Late Eocene in the central and western Iberian basins, on the basis that the perissodactyl fossils from the middle Headonian beds at Zambrana (Miranda-Trebiño Basin) are related to endemic taxa from the late Robiacian beds of the Duero, Almazán, and Oviedo Basins.

Bird and Mammal Footprints From the Tertiary of Navarre (Western Pyrenees)

A rich variety of vertebrate footprints is known from a number of Upper Eocene to Lower Miocene localities of Navarre (western Pyrenees). The sediments were deposited in a wide range of depositional environments, from marginal marine to diversified terrestrial. Abundant bird tracks have been found in the coastal deposits of the Upper Eocene Liedena Sandstone of the Yesa and Itzagaondoa areas. Ciconiiformes-like (Leptoptilostipus pyrenaicus) and Charadriiformes-like (Charadriipeda ichnospp.) footprints have been recognized. Mammal ichnites have been discovered in the Oligocene and Lower Miocene deposits of Navarre. Equoid perissodactyl ichnites similar to those of Plagiolophustipus occur in the Oligocene fluviatile rocks of the Mués Sandstone of Olexoa and the Rocaforte Sandstone near Oibar and Sada. Trackways of entelodontids (Entelodontipus) are known in fluviatile-palustrine beds of the Oligocene Mués Sandstone of Olkotz. Additionally, bird (Charadriiformes-like) tracks are known in fluviatile-palustrine floodplain deposits of the Lower Miocene Ujué Formation of Los Arcos. In the same area, the Desoio and Los Arcos outcrops have also yielded perissodactyl trackways of possible Equoidea. Trackways of rhinocerotids (?) and artiodactyls (possibly Pecoripeda) are described from the Lower Miocene (Ramblian) palustrine limestones marginal to the Lerín Formation of Kaparroso and from alluvial fan deposits of the Uncastillo-Perdón Formation of Altzorritz, respectively.

New dryolestidan mammal from the Hauterivian-Barremian transition of the Iberian Peninsula

Cuenca-Bescós, G., Badiola, A., Canudo, J.I., Gasca, J.M., and Moreno-Azanza, M. 2011. New dryolestidan mammal from the Hauterivian—Barremian transition of the Iberian Peninsula. Acta Palaeontologica Polonica 56 (2): 257–267. Crusafontia amoae sp. nov. (Dryolestida, Stem Cladotheria) is represented by two isolated upper molars (M4 or M5 and M6 or M7) from the terminal Hauterivian—basal Barremian (Early Cretaceous) of the El Castellar Formation (Galve, Spain). The molars have a deep ectoflexus, a distinct metacone, a continuous metacrista, and an antero-lingually placed paracone. They differ from the molars of the other species of the genus, Crusafontia cuencana, by their larger size, by their outsized parastyle, by the pointed lingual slope of the paracone, their more symmetrical appearance with a deep ectoflexus in occlusal view, and the well-developed metacone. Revision of three isolated teeth previously attributed to Crusafontia cuencana suggests that instead of being upper premolars belonging to Crusafontia cuencana they in fact belong to Pocamus pepelui, of the stem cladotherian superorder Zatheria, probably “peramuran”. As such, the stem Cladotheria record from the Early Cretaceous of the Iberian Peninsula is composed of two dryolestids (Crusafontia amoae and Crusafontia cuencana) and one zatherian (Pocamus pepelui). Key words: Mammalia, Cladotheria, Dryolestida, Crusafontia, systematics, Cretaceous, Iberian Peninsula.

The Upper Eocene South Pyrenean Coastal deposits (Liedena sandstone, navarre): Sedimentary facies, benthic formanifera and avian ichnology

SummaryDuring the 1960s and the 1970s the Liedena Sandstone was a type deposit for “flysch-like facies” (sandstone and lutite alternations) of coastal sedimentary systems. However, the depositional system of these beds was never accurately defined. The sedimentological analysis along 100 km of outcrops in the western part of the South Pyrenean Zone (Navarre) allows these peculiar facies to be assigned to a mixed intertidal flat. Furthermore, sandy beach facies, different types of heterolithic, backbarrier deposits and conglomeratic, fluviatile facies have been recognized associated with these intriguing deposits. Generally, a northwestward-facing barrier-island system or wave-dominated delta was the likely depositional environment.The benthic foraminiferal assemblage in the intertidal deposits exhibits the typical characteristics of a marginal marine environment: extremely high dominance of one species (Pararotalia inermis), low species diversity, and a hyaline dominance with discrete amounts of miliolids. Furthermore, the most abundant species indicates that the Liedena Sandstone was deposited during the Late Eocene.Abundant footprints of aquatic birds are known in the tidal flat deposits. Six morphotypes have been distinguished: two (types 1 and 2) are ciconiforme-like; type 1 is here assigned to a new ichnotaxon,Leptoptilostipus pyrenaicus and is one of the oldest occurrences of Ciconiiforme-like ischmites in the fossil record. Two other morphotypes (5 and 6) are similar to those of the Charadriiformes and are refeered to asCharadriipeda. Finally, the affinities of the two remainder morphotypes (3 and 4) are unclear, they could have been made by Charadriiformes.Synsedimentary tectonic activity controlled the evolution of the depositional system, as the area of deposition of the Liedena Sandstone was progressively incorporated into the active thrust sheets of the Pyrenean Orogen during the Late Eocene. The structural uplift and the large amount of sediments derived from the adjacent highlands induced progradation of the depositional system and the definitive retreat of the sea from the South Pyrenean Zone.

First record of the genus Microchoerus (Omomyidae, Primates) in the western Iberian Peninsula and its palaeobiogeographic implications.

In this paper we describe new material of Microchoerus (Microchoerinae, Omomyidae, Primates) from Zambrana (Miranda-Trebiño Basin, northern Iberian Peninsula, Spain), a locality assigned to Reference Level MP18 (middle Headonian, Late Eocene). The specimens studied consist of two mandibular fragments, bearing p3-m3 and p4-m3. The teeth resemble in size and morphology those of Microchoerus erinaceus from Hordle Cliff, England, although some differences prevent us from making a definitive ascription to this species. We therefore refer the material from Zambrana to Microchoerus aff. erinaceus. Some traits, such as the development of the mesoconid and hypoconulid in the m1 and m2, and the shape of the hypoconulid lobe in the m3, are intermediate between those of M. erinaceus and Microchoerus edwardsi. Thus, the material from Zambrana is very similar to other species of Microchoerus present in Europe, representing a transitional form between M. erinaceus and M. edwardsi. The described material represents the first discovery of a primate from the Miranda-Trebiño Basin, and also the westernmost record of the genus Microchoerus in the Iberian Peninsula. Moreover, the identification of this microchoerine, with clear similarities to the representatives of this genus described from other European sites, reinforces the idea of the existence of connections between western Iberia and the rest of Europe in the Late Eocene, previously hypothesized after the discovery of typical European artiodactyls in the site of Zambrana.

New fossils of Sirenia from the Middle Eocene of Navarre (Western Pyrenees): the oldest West European sea cow record

Postcranial remains of Sirenia from the early Middle Eocene (late Lutetian) Urbasa-Andia Formation of Navarre (Western Pyrenees) are described. The material consists of two partial atlas vertebrae, one humerus and several dorsal ribs (from Arrasate, Urbasa plateau), and partial dorsal ribs (from Lezaun, Andia plateau). The morphology of the fossils is consistent with referral to Dugongidae, the only sirenian clade known so far in the Middle Eocene of Europe. Moreover, the histological study of the ribs shows that the pachyosteosclerosis of extant Sirenia was definitively present by the early Middle Eocene. The oldest sirenian remains reported to date in the Pyrenean Realm were assigned to the Biarritzian, a regional stage that is currently ascribed either to the middle or to the lower–middle Bartonian. Therefore, the sirenian remains of Lezaun, reliably dated as late Lutetian (SBZ16 zone) in age, are definitively the earliest sirenian fossils known in Western Europe and are among the oldest sea cow records of Europe.

TAPHONOMY OF VERTEBRATE FOSSIL ASSEMBLAGES FROM SWAMPY CIRCUM-LAKE ENVIRONMENTS: AN EXAMPLE FROM THE LATE EOCENE OF ZAMBRANA (IBERIAN PENINSULA)

Abstract Biostratinomic and bone-diagenesis parameters are used to evaluate the effects of abiotic and biotic processes on the final composition of two late Eocene vertebrate assemblages preserved in a swampy circum-lake environment from the Zambrana site (Basque-Cantabrian Region, northern Iberian Peninsula). No significant transport or bone sorting by fluvial action is observed, and complete and fragmentary bones in the assemblages (Z4 and Z6 beds) show the same biostratinomic features. The attritional bone accumulation in both excavated beds was caused mostly by biotic factors related to routine ecological deaths of population members, probably with some input from predators on the most vulnerable ungulate individuals (autochthonous), although a weak input of small remains by superficial water currents from nearby areas (parautochthonous) cannot be rejected. The vegetation and wet conditions of the swampy environment, together with possible predator and scavenger activity, could have caused the disarticulation and dispersion of some vertebrate remains, mainly those of ungulates. The bones were buried relatively quickly in the phreatic zone under reducing conditions and suffered considerable crushing and fragmentation because of lithostratigraphic compaction. Mineralogic similarities between sedimentary fillings in the fossils and the host sediment, as well as the homogeneous rare earth element (REE) trends of the fossils, are indicative of a uniform and unique diagenetic history and the absence of reworked elements. The fossil bone mineral is well-crystallized francolite (carbonate fluorapatite). The REE enrichment of bones and their calcite and pyrite crusts and fillings were formed during early diagenetic phases. The black coloration of the bones may be explained by their high hydrocarbon (n-alkane components) contents.

DUEROTHERIUM SUDREI GEN. ET SP. NOV., A NEW ANOPLOTHERIINE ARTIODACTYL FROM THE MIDDLE EOCENE OF THE IBERIAN PENINSULA

Anoplotheriines were endemic artiodactyl faunas in Europe during the Eocene. Europe was made up of several large and small islands from the late Early Eocene to the earliest Oligocene (e.g., Meulenkamp et al., 2000), and was inhabited by an endemic mammalian fauna that was clearly different from contemporary faunae in North America and Asia. Ano plotheriines were medium- to large-sized ungulates with bra chydont and bunoseledont dentition and likely used terrestrial locomotion (Sudre, 1988). Hooker (2007) recognized a bipedal browsing adaptation for the large Anoplotherium species, which would have been able to browse 2-3 m above the ground with no competition from other contemporaneous European terrestrial mammals. Anoplotheriines are regarded as members of the immigrant taxa that appeared on the Cen tral European Island around the Middle-Late Eocene transi tion. They seem to have originated within Europe, but their area of origin and the dispersal directions that they took through the different areas of the Eocene European archipel ago are still poorly characterized. Here we describe a new anoplotheriine that is assigned to a new genus on the basis of a left maxilla fragment with the P3-M3

First adequately-known quadrupedal sirenian from Eurasia (Eocene, Bay of Biscay, Huesca, northeastern Spain)

Sirenians are the only extant herbivorous mammals fully adapted to an aquatic lifestyle. They originated in Africa during the Paleocene from an undetermined clade of afrotherian mammals, and by the end of the Eocene they were widely distributed across the tropical latitudes. Here we introduce Sobrarbesiren cardieli gen. et sp. nov. It is the first adequately-known quadrupedal sirenian from Eurasia and the oldest record of this clade from western Europe. Fossils have been recovered from the middle Lutetian (SBZ15) site of Castejón de Sobrarbe-41 (Huesca, Spain), and comprise many cranial and postcranial remains, including pelvic girdle and hind limb bones, from at least six sirenian individuals of different ontogenetic stages. Sobrarbesiren shows a suite of characters previously considered synapomorphies of different clades of derived sirenians, such as the presence of the processus retroversus of the squamosal and the pterygoid fossa, combined with ancestral characters such as the presence of an alisphenoid canal, a permanent P5, at least two sacral vertebrae, a primitive pelvis and functional femora and fibulae. Sobrarbesiren is recovered as the sister taxon of Dugongidae and represents a transitional stage of adaptation to aquatic life between the amphibious quadrupedal prorastomids and the aquatic quadrupedal protosirenids.