Ana Márquez-Aliaga

Pseudodalatias henarejensis nov. sp. A New Pseudodalatiid (Elasmobranchii) from the Middle Triassic of Spain

ABSTRACT Pseudodalatiids, a chondrichthyan family of uncertain phylogenetic affinities, have been hitherto exclusively known from the tooth-based species Pseudodalatias barnstonensis (Sykes, 1971), which has a stratigraphic range restricted to the Upper Triassic of Europe. Pseudodalatias presents a characteristic dentition which allows it to hold and cut its prey, showing a neoselachian design, but lacking the triple-layered enameloid microstructure of neoselachian teeth. The discovery of Pseudodalatias henarejensis nov. sp. in the Ladinian of Spain extends the stratigraphical range and the palaeogeographical distribution of this family. This new species also demonstrates that a cutting-clutching dentition evolved progressively in the family Pseudodalatidiidae. Pseudodalatiids are likely to represent stem-batoids or stemneoselachians rather than aberrant hybodonts.

Triassic lingulide brachiopods from the Iberian range (Spain)

Abstract During the Middle Triassic marine transgression in Spain, several lingulide populations were fossilized in the Iberian Range (western part of Sephardic Province) and the recorded specimens have been described previously under several specific names. The paleontological aspects of the Jalance (Valencia province) section have been studied for the first time. Its exceptionally large population was fossilized in situ as flat-lying valves and can be interpreted as an autochthonous association related to a very shallow marine environment. The lingulide specimens belong to the genus Lingularia Biernat & Emig , 1993 , but the species name remains under debate, probably Lingularia smirnovae. Internal morphology and shell characters are described and compared with other Lingularia species.

The chondrichthyan fauna from the Middle Triassic (Ladinian) of the Iberian Range (Spain)

ABSTRACT Here we present for the first time a detailed taxonomic study of a diverse chondrichthyan fauna from the Middle Triassic of the Iberian Range (Spain). The assemblage consists of isolated remains of seven species of five non-neoselachian shark genera (Palaeobates, Hybodus, Pseudodalatias, Prolatodon, gen. nov., and Lissodus), including a new species of hybodontiform shark, Hybodus bugarensis, sp. nov. In addition, a new homalodontid genus, Prolatodon, sp. nov., is erected for the taxa ‘Polyacrodus’ bucheri and ‘Polyacrodus’ contrarius. The chondrichthyans of the Iberian Range represent a heterogeneous group from a paleogeographic point of view made up of common components of Middle Triassic shark faunas of northern Europe (Hybodus plicatilis and Palaeobates angustisimus) together with species only known previously from North America and China (Prolatodon bucheri, comb. nov., and Prolatodon contrarius, comb. nov.), as well as several ‘endemic’ taxa (Pseudodalatias henarejensis, Hybodus bugarensis, sp. nov., and Lissodus aff. L. lepagei). This fauna demonstrated adaptation for a wide diversity of feeding strategies, implying that non-neoselachian sharks dominated among the predator community of Middle Triassic coastal ecosystems of Iberia. The co-occurrence with bivalves, ammonoids, and conodonts allows us to date the chondrichthyan assemblage as ‘Longobardian’ (upper Ladinian).

Ladinian carbonates of the Cabo Cope Unit (Betic Cordillera, SE Spain): a tethys-maláguide palaeogeographic gateway

SummaryThe Cabo Cope Unit, which outcrops east of Aguilas (Murcia), belongs to the Maláguide tectonic Complex (Betic Internal Zone) and displays stratigraphic characteristics of particular interest, including Triassic bioclastic carbonate beds which are not common in the Maláguide units. Biostratigrafic fossils have been found in these beds and may correlate with Triassic alpine biofacies. Alpine fauna fossils only appeared in those palaeogeographic units of the Internal Zone of the Cordillera referred to as Alpujárride units, while the influence of the Sephardic faunal province is evident in almost all the cordillera. For these reasons it is noteworthy that new alpine fauna fossils have been found in an Internal Zone unit in which relevant fossils rarely appear. The Triassic succession of the unit studied in this paper can be subdivided into two members: a lower one, which is clastic and contains thick gypsum beds, and an upper one, consisting of carbonate rocks. The lower member has been interpreted as a fluvial-coastal deposit. The upper member is interpreted as a sequence of carbonate ramp deposits. This ramp evolved into a shallow platform with tidal flats typical of a coastal zone. The bivalve fossilsDaonella cf.lommeli (Wissmann) and “Posidonia” sp. have been found in the carbonate member, along with the conodontSephardiella mungoensis (Diebel). These fossils are of the Late Ladinian age and have been found only in this outcroup of the Betic Cordillera. The presence of this fossil assemblage, which belongs to the alpine faunal province, indicates a connection during the Late Ladinian between the Tethys sea and this area of the Maláguide palaeogeographic domain. The palaeogeographic location of the Cabo Cope Unit during the Middle Triassic was at the south-easternmost part of the Betic Basin, implying that the connection between the Tethys and the Betic Basin was established in the easternmost domains of the basin.

Taxonomy and evolution of the Triassic conodont Pseudofurnishius.

Pseudofurnishius is a late Anisian (Pelsonian)—early Carnian (Cordevolian) conodont genus of gondolellid stock, characteristic for the Sephardic Province and restricted to the “Southern Tethys” region of the northern margin of Gondwana. Its most commonly found species, Pseudofurnishius murcianus, appears at the base of the Ladinian (Fassanian). The Ladinian material of Spain reveals its ontogeny characterised by initial lateral protrusions from the carina that may develop first mono-platform and later bi-platform units, finally evolving into elaborated multi-denticulated forms. The late Anisian—early Carnian phylogenesis of Pseudofurnishius priscus → P. shagami → P. murcianus is proposed. At the end of the Ladinian, Pseudofurnishius expanded to the entire “Southern Tethys” shelf and into Cimmerian terranes that drifted away from northern Gondwana, now accreted to Eurasia, such as the Sibumasu terrane (Southwest China—Malayan Peninsula).

The Duplivincular Ligament of Recent Pinna Nobilis L., 1758: Further Evidence for Pterineid Ancestry of the Pinnoidea

A correct interpretation of ligament ontogeny and structure is essential for establishing phylogenetic relationships among higher taxa in the bivalve superorder Pteriomorphia. Recent research on pteriomorphian ligaments has focused on understanding ligament morphospace (Thomas et al., 2000; Ubukata, 2003) and evolutionary pathways. In this regard, studies of the transition from larval to post-larval and adult ligaments (Malchus, 2004) have been especially fruitful. Members of the pteriomorphian superfamily Pinnoidea live with their tapered anterior end buried to varying degrees in sediment. The fan shell Pinna may be buried up to one third of its length (Templado, 2004) (Fig. 1), and Atrina is even more completely buried (Hippeau-Jaquotte, 1974). Under these circumstances, shell gaping for respiration and feeding might be expected to allow sediment to enter the mantle cavity. Pinnoidean mantle lobes, unlike those of many other infaunal bivalves, are not extensively fused ventrally (Yonge, 1953). Sediment is largely excluded from entering the ventral shell margins because the pinnoidean ligament has lost its shell-opening and closing function and merely holds the dorsal and, indirectly, the ventral shell margins together. Shell opening is restricted in this genus to the extreme posterior end, where the calcitic prismatic outer shell layer flexes to open the shell when the posterior adductor muscle is relaxed (Yonge, 1953; Carter, 1990, p. 212). In Streptopinna , the shell valves are uniquely fused together dorsoposteriorly by the calcitic outer shell layer (Cox and Hertlein, 1969; Waller, 1990).  Figure 1 —Drawing of a Pinna nobilis individual as is usually found with the tapered anterior third of the shell buried in the sediment, attached to the substratum by byssus threads. Each rectangle delimits the portions of the shell shown in subsequent figures The pinnoidean ligament has traditionally been described as subinternal, opisthodetic with a single couplet …

Bivalves from the Triassic−Jurassic transition in northern Spain (Asturias and western Basque−Cantabrian Basin)

Abstract. Bivalve mollusks from the Triassic-Jurassic transition collected in eight localities in Asturias and the western Basque-Cantabrian Basin (Palencia province) are systematically revised. Preservation is poor at all localities. The dominant Rhaetian bivalves are Isocyprina concentrica (Moore) and Bakevellia (Bakevelloides) praecursor (Quenstedt). These species, together with Isocyprina cf. ewaldi (Bornemann), Pteromya cf. crowcombeia (Moore), Pseudoplacunopsis alpina (Winkler), and Modiolus? sp. (cf. minimus J. Sowerby), with a specimen of Arcestidae (?), belong to an assemblage similar to that found in the Westbury and Lilstock formations (Penarth Group) in the late Rhaetian of southern England. The most abundant Hettangian species is Isocyprina (Eotrapezium) germari (Dunker). Others are referred to Cuneigervillia rhombica (Cossmann), Sphaeriola? sp., Eomiodon? sp. and Pteromya cf. tatei (Richardson and Tutcher). All Hettangian shell beds examined are monotypic or have very low diversity, a biological indication that they may belong to a restricted marine environment, with high environmental stress levels. Even the more diverse assemblage (Pteromya-Cuneigervillia-Eomiodon) was probably also salinity controlled. The fauna analyzed here clearly belongs to the same facies and environment as those described from Aquitaine (France) and the Pyrenees and is different from coeval bivalve assemblages from other European Hettangian localities. The Triassic-Jurassic boundary cannot be precisely located at the studied sections on the basis of the bivalve faunas alone, but these indicate that the transition beds in Asturias were deposited in a marginal marine environment and the benthic fauna was dominated by shallow burrowing, suspensivorous bivalves.

An enigmatic marine reptile, Hispaniasaurus cranioelongatus (gen. et sp. nov.) with nothosauroid affinities from the Ladinian of the Iberian Range (Spain)

Abstract An incomplete skull of a marine reptile with an atypical elongation of the postorbital region is described. The find comes from the Muschelkalk facies (Cañete Formation) of the Villora section (Iberian Range, Cuenca Province, Spain), characterised by a shallow marine (intertidal) environment and dated as Ladinian in age. The small skull has a rectangular shape, lacking, as preserved, upper temporal openings and a parietal foramen. The upper temporal openings might be secondarily closed. However, the absence of a parietal foramen and squamosals in the preserved part and the incompleteness of the pterygoids make a posteriorly postponed location of the upper temporal openings also conceivable. Teeth are all broken off but alveolar spaces indicate large and massive maxillary dentition. Micro-CT-data revealed a highly vascularised inner structure of the dorsal skull elements, which might indicate special feeding adaptations. Adding the new find to an existing phylogenetic analysis of Triassic marine reptiles reveals eosauropterygian, especially nothosauroid, affinities. However, morphological differences to nothosauroids justify the erection of a new genus and species for this enigmatic marine reptile. Its atypical morphology, without any extinct or modern analogue, fits well with the continuously increasing diversity of Triassic marine reptiles, exhibiting various specialised feeding strategies urn:lsid:zoobank.org:act:6D75AEC7-A5C5-4844-B71A-8215AB099134

Parainoceramya n. gen. for Parainoceramus Cox, 1954 ( ex Voronetz, 1936) partim (Bivalvia, Jurassic)

Abstract. Several Jurassic pterioid bivalve species have been referred to Parainoceramus Cox by different authors, yet this has proved inadequate because the meaning of such genus has been compounded by nomenclatural and idiomatic problems, as well as misinterpretations. Hence, the new genus Parainoceramya is here proposed to accommodate several species previously referred to Parainoceramus, with Crenatula ventricosa J. de C. Sowerby as its type. Permian species originally assigned to Parainoceramus, including the type species, are referred to the genus Kolymia Likharev. All species attributed to Parainoceramus s.l. are reviewed and the new genus is compared with related genera. As here understood, the new genus is first recorded in the Hettangian and attained a cosmopolitan distribution; its last occurrence is probably Berriasian.