New occurrences of the wood Protocupressinoxylon purbeckensis Francis: implications for terrestrial biomes in southwestern Europe at the Jurassic/Cretaceous boundary

Abstract:  Previously known from the Kimmeridgian–Portlandian of Dorset (UK) only, Protocupressinoxylon purbeckensis wood is reported here from the Kimmeridgian of Asturias (Spain) and Ajoie (Switzerland). The morphospecies taxonomy and nomenclature are discussed, and new supplementary illustrations are given. The P. purbeckensis tree was growing in dry strongly seasonal (tropophilous) environments, and the new occurrences suggest that such a climate prevailed on land all over southwestern Europe at the end of the Jurassic (Kimmeridgian sensu anglico – Portlandian). The review of fossil wood data indicates that such a stressful environment may have constrained terrestrial biocoenoses and their evolution at the Jurassic/Cretaceous boundary. But wood generic diversity curves are also strikingly similar to that drawn 20 years ago for nonmarine tetrapods, implying a fossil Lagerstätte effect.     

A REVISION OF THE FOSSIL PIRATE SPIDERS (ARACHNIDA: ARANEAE: MIMETIDAE)

Abstract:  Fossil pirate spiders (Araneae: Mimetidae) are revised. The extinct genera Succinero Wunderlich, 2004 a and Palaeoero Wunderlich, 2004 a are interpreted as synonyms of the extant genus Ero C. L. Koch, 1836. We recognize here the following fossil species as valid: E. carboneana Petrunkevitch, 1942, E. longitarsus (Wunderlich, 2004 a ) comb. nov. and E. permunda Petrunkevitch, 1942, all from Baltic amber (Paleogene: Eocene), and E. rovnoensis (Wunderlich, 2004 b ) comb. nov. from Rovno (Ukranian) amber (Paleogene: Eocene). Mimetus bituberculatus Wunderlich, 1988 from Dominican Republic amber (Neogene: Miocene) can be assigned to a specifically American clade of Mimetus Hentz, 1932. Mimetus brevipes Wunderlich, 2004 a from Baltic amber is synonymized with M. longipes Wunderlich, 2004 a syn. nov. Of the other species (all Baltic amber), Ero aberrans Petrunkevitch, 1958 lacks taxonomically useful characters. Ero setulosa C. L. Koch and Berendt, 1854 is based on two non-conspecific, and non-mimetid, spiders. Mimetarchaea gintaras Eskov, 1992 is a subadult male mimetid. The putative oarcine 'missing link' Praeoarces exitus Wunderlich, 2004 a is a subadult female mimetine. All four are treated here as nomina dubia . Other fossil mimetid species in the literature are nomina nuda .     

ROOTING PHYLOGENIES OF PROBLEMATIC FOSSIL TAXA; A CASE STUDY USING CINCTANS (STEM-GROUP ECHINODERMS)

Abstract:  Extinct clades whose higher-level relationships are problematic or disputed pose a particular problem for phylogenetic analysis because of the difficulty of establishing a convincing root. Cinctans are a problematic group of primitive preradiate echinoderms whose morphology is so distinct that few characters can be usefully homologized with any other group. Here we use a two stage approach, first constructing an unrooted network using the totality of phylogenetically informative characters in which individual plates are homologized, and then determining the root position with a much smaller set of recast characters that can be polarized by outgroup and/or ontogenetic criteria. Furthermore, when rooting is based on stratigraphic criteria the same two major derived clades are identified, although basal relationships are somewhat different. We contend that the congruence of results obtained using our various approaches provides confidence that we have correctly rooted the cladogram. A revised taxonomy for Cincta is presented.     

AN EOCENE FROGFISH FROM MONTE BOLCA, ITALY: THE EARLIEST KNOWN SKELETAL RECORD FOR THE FAMILY

Abstract:  Eophryne  barbutii gen. et sp. nov., a new frogfish from the Ypresian of Monte Bolca (Italy), is described. This taxon is the oldest member of the family Antennariidae known to date based on articulated skeletal remains. Eophryne  barbutii gen. et sp. nov. possesses a unique combination of features that supports its recognition as a new genus of the family Antennariidae. It is characterized by the presence of tiny bifurcated dermal spinules on the skin between and on the surface of the second and third dorsal-fin spines, a naked illicium, outermost caudal-fin rays simple, caudal peduncle present, 11 dorsal-fin rays, and seven anal-fin rays. Eophryne gen. nov. shows a certain degree of phenetic resemblance to the extant genera Antennarius , Histrio and Nudiantennarius . Palaeoecological and evolutionary implications are also discussed.     

Representing supraspecific taxa in higher-level phylogenetic analyses: guidelines for palaeontologists

Abstract:  As phylogenetic analyses become larger, one of the greatest methodological difficulties is representing speciose supraspecific clades in higher-level analyses (e.g. trilobites within studies of arthropod phylogeny). Several strategies have been proposed, including using representative single composite terminals or species-level exemplars, and various methods are currently used in the palaeontological literature. However, this is problematic, as simulation studies and empirical arguments in the systematics literature have clearly identified multiple exemplars as the optimal method. The continuing usage of suboptimal strategies in palaeontology may lessen the accuracy of phylogenies and hampers comparison between alternative studies. Here, I outline problems with suboptimal strategies, review arguments in support of multiple exemplars and provide guidelines for palaeontologists undertaking higher-level phylogenetic analyses.     

EARLY LLANDOVERY CHITINOZOANS FROM JORDAN

Abstract:  Chitinozoans recovered from cores BG-14 and WS-6 in southern and eastern Jordan are described. Sample ages are well-constrained by graptolite data to the ascensus-acuminatus and vesiculosus graptolite biozones. Eighteen chitinozoan taxa are recognized, with Spinachitina  fragilis , Plectochitina  nodifera , Ancyrochitina  laevaensis and Belonechitina  postrobusta allowing correlation with both local and global chitinozoan and graptolite biozonations for the Rhuddanian. One new species of chitinozoan is erected, Belonechitina  pseudarabiensis sp. nov.     

ORDOVICIAN FISH FROM THE ARABIAN PENINSULA

Abstract:  Over the past three decades Ordovician pteraspidomorphs (armoured jawless fish) have been recorded from the fringes of the Gondwana palaeocontinent, in particular Australia and South America. These occurrences are dominated by arandaspid agnathans, the oldest known group of vertebrates with extensive biomineralisation of the dermoskeleton. Here we describe specimens of arandaspid agnathans, referable to the genus Sacabambaspis Gagnier, Blieck and Rodrigo, from the Ordovician of Oman, which represent the earliest record of pteraspidomorphs from the Arabian margin of Gondwana. These are among the oldest arandaspids known, and greatly extend the palaeogeographical distribution of the clade around the periGondwanan margin. Their occurrence within a very narrow, nearshore ecological niche suggests that similar Middle Ordovician palaeoenvironmental settings should be targeted for further sampling.     

The Upper Tremadocian (Ordovician) graptolite Bryograptus: taxonomy, biostratigraphy and biogeography

Abstract:  The taxonomy, biostratigraphical and palaeogeographical distribution of the Lower Ordovician graptolite genus Bryograptus is evaluated. Bryograptus is recognized as a distinct triradiate anisograptid with a multiramous, pendent rhabdosome. The species of the genus Bryograptus can be interpreted as shallow water faunal elements with a strongly limited biogeographical distribution to the Atlantic Faunal Realm. Bryograptus is restricted to a narrow interval in the Upper Tremadocian, the Bryograptus Biozone of Scandinavia and South America (Argentina), making it a taxon with a high potential for precise biostratigraphical correlations. The proximal end development can be used to differentiate the genus Bryograptus from other pendent multiramous graptoloid genera with a homoplastic rhabdosome development. Characteristics of the proximal end development and structure easily differentiate these genera in relief specimens, but not in flattened material.