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1.
The Hexanchiformes (Cow Sharks) are regarded as a monophyletic taxon. Cladistic analysis shows that among the various neoselachian taxa proposed so far as the sister group of the Hexanchiformes a sister group relationship between the Hexanchiformes and a (still unnamed) taxon comprising the Squaliformes and Pristiophoriformes appears as the most probable hypothesis. In addition, MAISEY and WOLFRAM'S (1984) concept of hexanchiform interrelationships is critically reviewed. An alternative cladogram of hexanchiform interrelationships is developed which includes Recent as well as fossil hexanchiform taxa. In this cladogram the living genera Hexancbus and Notorynchus are sister groups and both taxa together form the sister group of the Recent Heptranchias. The fossil taxa +Notidanoides, +“Hexanchus” gracilis, +Notidanodon and +Weltonia are arranged in the stem lineage of recent Hexanchiformes.  相似文献   

2.
Present groupings of Caridea are notoriously unsatisfactory at the superfamily level. Principles of phylogenetic systematics are used to reconstruct 14 monophyletic subgroups of Caridea, based on 19 synaomorphies of adults. The following sequenced phylogenetic classification is provided (main diagnostic character for each superfamily within brackets): 1. Atyoidea (distal lash of Mxp, reduced); Oplophoridae; Atyidae; Pasiphaidae; Agostocarididae; Alvinocarididae; Bresiliidae; Psalidopodidae; Disciadidae; 2. Stylodactyloidea (mandibular palp with 2 segments or absent); Stylodactylidea; Campylonotidae; 3. Eugonatonotoidea (abdominal somite III with dorsal carina bifurcate); Eugonatonotidae; 4. Palaemonoidea (basal segment of antennular peduncle with distolateral tooth); Rhynchocinetidae; Palaemonidae; 5. Nematocarcinoidea (ventral lobe of scaphognathite narrowly triangular); Nematocarcinidae; 6. Pandaloidea (P1 with chela microscoic or absent); Pandalidae; “Plesionikidae”; Heterocarpidae; Heterocarpoididae; Dorodoteidae; Thalassocarididae; Physetocarididae; 7. Crangonoidea (incisor process of mandible absent); Barbouriidae; Lysmatidae; Merguiidae, fam. n.; Processidae; Glyphocrangonidae; Crangonidae; 8. Alpheoidea (carpus of P2 with less than 17 segments); Merhippolytidae, fam. n.; Nauticarididae; Alopidae; Bythocarididae; Thoridae; Hippolytidae; Pterocarididae, fam. n.; Ogyrididae; Alpheidae. The monotypic hippolytid taxon Thorellinae, subfam. n., has been formally diagnosed. A survey of the lower Caridea has furnished 276 enera and 2418 species and subspecies. The new superfamily system is simpler, genealogically informative and more precisely diagnosed than previous schemes. These have failed as general reference systems because they were based on the wrong premises that similarities indicate phylogenetic relationships or can be used to construct a single acceptable hierarchy.  相似文献   

3.
More than 100 species of gastropods from vent and seep localities around the world are reviewed, based on literature information and new material. The following new taxa are described (localities with parentheses, systematic position within brackets): Cantrainea macleani sp.n. (Louisiana Slope) [Turbinidae]; Fucaria striata gen. et sp.n. (Juan de Fuca Ridge area), Vetuloniaphalcata sp.n. (North Fiji Basin) [both Trochidae]; Protolira valvatoides gen. et sp.n. (Mid-Atlantic Ridge) [Skeneidae]; Ventsia tricarinata gen. et sp.n. (Lau Basin), Bruceiella globulus gen. et sp.n. (Lau Basin) [both tentatively in Skeneidae]; Melanodrymia brightae sp.n. (Juan de Fuca Ridge area), Pachydermia sculpta sp.n. (Lau Basin), Planorbidella gen.n., P. depressa sp.n. (Lau Basin), Ctenopelta porifera gen. et sp.n. (EPR 13°N)[Peltospiridae]; Helicrenion reticulatum gen. et sp.n. (Lau Basin), Lepfogyra inflata sp.n. (Lau Basin) [families unknown]; Desbruyeresia spinosa gen. et sp.n. (Lau Basin), D. cancellata sp.n.(Lau Basin), D. melanioides sp.n. (Lau Basin), Provanna buccinoides sp.n. (Lau Basin) [Provannidae]; Hyalogyra vitrinelloides sp.n. (Lau Basin), Hyalogyrina grasslei s p a (Guaymas Basin)[Hyalogyrinidae fam. n.], Xylodiscula major sp.n. (North Fiji Basin) [Xylodisculidae]. The external morphology of the soft parts [for Ifremeria and Alviniconcha (Provannidae) also the anatomy] is described for most of the taxa involved. Some features in the biology and distribution of the gastropod fauna are discussed. About half the fauna consists of species belonging to families or superfamilies endemic to this environment. One-fifth of the remaining species belong to taxa normally associated with biogenic substrates in the deep sea. Alviniconcha hessleri has previously been shown to harbour chemosynthetic bacteria in the gill; Ifremeria nautilei is here confirmed to do the same. Ctenopelta porifera, and Hirtopelta hirta are suspected to have such bacteria because of reduction of the alimentary system.  相似文献   

4.
Cladistic analyses of 17 wild and cultivated pea taxa were performed using morphological characters, and allozyme and RAPD (random amplified polymorphic DNA) markers. Both branch-and-bound and bootstrap searches produced cladograms that confirmed the close relationships among the wild species and cultivars of Pisum proposed by a variety of systematic studies. Intraspecific rankings were supported for northern P. humile, southern P. humile, P. elatius and P. sativum, which together comprise a single-species complex. P. fulvum, while clearly the most divergent of the pea taxa, could also be assigned to the same species complex without violating the hierarchial logic of the cladogram. Its inclusion or exclusion depends on whether the level of interfertility it displays with other pea taxa or its overall morphological and chromosomal distinction are emphasized. As suggested by previous studies, northern P. humile was the most likely sister taxon to cultivated P. sativum; although, rigorous phylogenetic evaluation revealed a close genealogical affinity among P. elatius, northern P. humile and P. sativum. Despite their limited number, the 16 morphological characters and allozyme markers used precisely organized the pea taxa into established taxonomic groupings, perhaps in part reflecting the role morphology has played historically in pea classification. The RAPD data also generally supported these same groupings and provided additional information regarding the relationships among the taxa. Given that RAPDs are relatively quick and easy to use, are refractory to many environmental influences, can be generated in large numbers, and can complement traditional characters that may be limited in availability, they provide a valuable new resource for phylogenetic studies.  相似文献   

5.
A revision of the Jurassic aphid family Genaphididae revealed that the type genus Genaphis did not have the characteristics usually attributed to this family. This discovery led to a series of taxonomic decisions. The diagnosis of the family Genaphididae is emended. The genera Aphaorus, Juraphis and Pterotella are moved to the Juraphididae, fam.n. The new family is included in the superfamily Palaeoaphidoidea. Additionally, two new species, Juraphis karataviensis sp.n. and Pterotella shartegensis sp.n. , are described. Phylogenetic relationships among the taxa of Juraphididae, the position of the family, and the distribution and palaeoecology of the taxa are discussed. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:411C1D8C‐AA45‐4311‐AA2D‐4469E44B6EDF .  相似文献   

6.
An hypothesis of phylogenetic relationships of Asilidae and its constituent taxa is presented, combining morphological and DNA sequence data in a total evidence framework. It is based on 77 robber fly species, 11 Asiloidea outgroup species, 211 morphological characters of the adult fly, and approximately 7300 bp of nuclear DNA from five genes (18S and 28S rDNA, AATS, CAD, and EF-1α protein-encoding DNA). The equally weighted, simultaneous parsimony analysis under dynamic homology in POY resulted in a single most parsimonious cladogram with a cost of 27,582 (iterative pass optimization; 27,703 under regular direct optimization). Six of the 12 included subfamily taxa are recovered as monophyletic. Trigonomiminae, previously always considered as monophyletic based on morphology, is shown to be non-monophyletic. Two of the three Trigonomiminae genera, Holcocephala Jaennicke, 1867 and Rhipidocephala Hermann, 1926, group unexpectedly as the sister taxon to all other Asilidae. Laphriinae, previously seen in the latter position, is the sister group of the remaining Asilidae. Five other subfamily taxa, i.e. Brachyrhopalinae, Dasypogoninae, Stenopogoninae, Tillobromatinae, and Willistonininae, are also shown to be non-monophyletic. The phylogenetic relationships among the higher-level taxa are partly at odds with findings of a recently published morphological study based on more extensive taxon sampling. The total evidence hypothesis is considered as the most informative one, but the respective topologies from the total-evidence, morphology-only, and molecular-only analyses are compared and contrasted in order to discuss the signals from morphological versus molecular data, and to analyze whether the molecular data outcompete the fewer morphological characters. A clade Apioceridae+Mydidae is corroborated as the sister taxon to Asilidae.  相似文献   

7.
Various characters of semiaquatic bugs belonging to the family Hebridae are analysed with respect to their taxonomic and phylogenetic importance. The cladistic relationships of the genera are discussed and a cladogram included. A classification is presented which divides the family into two sub-families and resurrects Lipogomphus Berg as a valid taxon (to include L. lacuniferus Berg (type-species), L.accola (Drake & Chapman) comb.n. for Merragata accola, L.brevis (Champion) comb.n. for Merragata brevis, and L.leucosticta (Champion) comb.n. for Merragata leucosticta). The following new taxa of hygropetric hebrids are described: Timasius livens sp.n. (Thailand), T.minor sp.n. (Pakistan, N. India), T.miyamotoi sp.n. (Thailand), T.major sp.n. (N.India), T.ventralis sp.n. (N. India), T. miyamotoi sp.n. (S. India), T.rupestris sp.n. (N. India), T.falcifer sp.n. (N. India), T.championi sp.n. (N. India), T.himalayensis sp.n. (N. India), Neotimasius orientalis gen.n., sp.n. (S. India), Hyrcaninae subfam.n. , Hyrcanus dispar sp.n. (N. India), H.saxatilis sp.n. (Thailand) and H.varicolor sp.n. (Java, Sumatra). Other species of the genera Timasius and Hyrcanus are redescribed and the generic position of one species changed: Hebrus (s.str.) atratus (Distant) comb.n. for Timasius atratus.  相似文献   

8.
At Cedro Peak (Manzanita Mountains, central New Mexico), the Pennsylvanian succession is divided into four formations: Sandia, Gray Mesa, Atrasado, and lower part of Bursum. The sampled limestones of the Gray Mesa and Atravasado formations yielded three age distinctive fossil assemblages: (a) latest Atokan/early Desmoinesian; (b) late early Desmoinesian, and (c) middle Virgilian. The calcareous algae, incertae sedis algae and cyanobacterial-foraminiferal consortia are described here. The following new taxa are named: Epimastoporaceae n. fam.; Anthracoporellopsis novamexicana n. sp.; Tubiphytidae n. fam.; and Latitubiphytes n. gen.  相似文献   

9.
Abstract. The status of the tribe Antillocorini as it occurs in the Western Hemisphere is discussed. An evaluation of characters useful in systematic analysis is included together with an evaluation of the plesiomorphic and apomorphic character states. The phylogenetic relationships of the genera are discussed and a cladogram included. A key is given to all known genera found in the Western Hemisphere. The following new taxa are described: Paradema gen.n.; Paradema bathydemoides sp.n. (Venezuela), P.engiernani sp.n. (Panama), P.longisetosa sp.n. (Argentina), P.oculata sp.n. (Coiumbia, Guyane) (type-species), P.pameroides sp.n. (Brazil), Caeneusia obrienorum sp.n. (Peru), Antillodema gen.n. (to include Antillocoris obscurus Barber comb.n. (type-species) and Bathydema maculosa Slater and Baranowski comb.n.), Paurocoris gen.n., P.yvgodzinskyi sp.n. (type-species) (Ecuador, Brazil, Peru, Argentina, Venezuela), P.punctata (Distant) transferred to Paurocoris from Bathydema, Trachinocoris gen.n., T.crassus sp.n. (Brazil), Terenocoris gen.n., T.nitidus sp.n. (Peru).  相似文献   

10.
Consensus is elusive regarding the phylogenetic relationships among neornithine (crown clade) birds. The ongoing debate over their deep divergences is despite recent increases in available molecular sequence data and the publication of several larger morphological data sets. In the present study, the phylogenetic relationships among 43 neornithine higher taxa are addressed using a data set of 148 osteological and soft tissue characters, which is one of the largest to date. The Mesozoic non‐neornithine birds Apsaravis, Hesperornis, and Ichthyornis are used as outgroup taxa for this analysis. Thus, for the first time, a broad array of morphological characters (including both cranial and postcranial characters) are analyzed for an ingroup densely sampling Neornithes, with crown clade outgroups used to polarize these characters. The strict consensus cladogram of two most parsimonious trees resultant from 1000 replicate heuristic searches (random stepwise addition, tree‐bisection‐reconnection) recovered several previously identified clades; the at‐one‐time contentious clades Galloanseres (waterfowl, fowl, and allies) and Palaeognathae were supported. Most notably, our analysis recovered monophyly of Neoaves, i.e., all neognathous birds to the exclusion of the Galloanseres, although this clade was weakly supported. The recently proposed sister taxon relationship between Steatornithidae (oilbird) and Trogonidae (trogons) was recovered. The traditional taxon “Falconiformes” (Cathartidae, Sagittariidae, Accipitridae, and Falconidae) was not found to be monophyletic, as Strigiformes (owls) are placed as the sister taxon of (Falconidae + Accipitridae). Monophyly of the traditional “Gruiformes” (cranes and allies) and ”Ciconiiformes” (storks and allies) was also not recovered. The primary analysis resulted in support for a sister group relationship between Gaviidae (loons) and Podicipedidae (grebes)—foot‐propelled diving birds that share many features of the pelvis and hind limb. Exclusion of Gaviidae and reanalysis of the data set, however, recovered the sister group relationship between Phoenicopteridae (flamingos) and grebes recently proposed from molecular sequence data.  相似文献   

11.
12.
Four new species of algae and two kinds of fossil plant hairs are described from a rich oil shale bed of the mid-Eocene Green River Formation of Wyoming. Two of the algae belong to the Cyanophyceae and two to the Chlorophyceae. On the basis of their morphology alone, they are assigned to four new species among four genera, as follows: Symploca hedraia, sp. n.; Stigonema anchistina, sp. n.; Schizochlamys haywellensis, sp. n.; and Spirogyra wyomingia, sp. n. One kind of fossil plant hair is similar to those observed in organic sediments of an existing lake and identified with trichomes on the under surface of live oak leaves (Quercus virginiana). Assignment of the fossil trichomes to a taxon is not warranted at present.  相似文献   

13.
Representatives of the Meidiamidae and Otomesostomidae (Platyhelminthes: Proseriata) are seldom encountered, and the monophyly and phylogenetic relationships of these families have never been assessed on molecular basis. Here, we present the first exhaustive molecular study of Proseriata at the family level, including species belonging to the genera Meidiama and Yorknia (Meidiamidae), and Otomesostoma auditivum (Otomesostomidae), using 18S and 28S genes as markers. We performed phylogenetic analyses (Maximum Likelihood [ML] and Bayesian Inference [BI] methods) and species delimitation methods (Single/Multiple Threshold‐Generalized Mixed Yule Coalescent [ST/MT‐GMYC] and Poisson Tree Processes [PTP/bPTP]). The taxon Meidiamidae was not supported, since the type species (Meidiama lutheri) and Meidiama etrusca sp. n. are nested within the Archimonocelididae, formerly restricted to specialized cnidarian feeders. Species belonging to the genus Yorknia resulted genetically well separated from species of Meidiama and from the rest of Archimonocelididae. The new family‐level taxon Yorkniidae fam. n. is thus here introduced, to include the type species of Yorknia (Yorknia aprostatica), and six new species, five of which are formally described here. Otomesostoma auditivum, representative of Otomesostomidae, the only exclusively freshwater taxon of the Proseriata, is the sister taxon of the predominantly marine Apingospermata. This result is not conflictual with the family level attributed to Otomesostomidae on morphological grounds, but it raises speculations on the marine versus freshwater origin of Apingospermata.  相似文献   

14.
《Systematic Entomology》2018,43(1):147-165
Morphological, anatomical, and distributional data concerning the S outh A frican endemic beetle subtribe P ythiopina (T enebrionidae: P edinini) are revised. Five species, representing two genera, are recognized. Included in this total is one new species (Meglyphus mariae K amiński sp.n. ). The following species are placed in synonymy: Meglyphus ciliatipes [=Meglyphus calitzensis syn.n. ]; Meglyphus laenoides [=Meglyphus andreaei syn.n. ; =Meglyphus namaqua syn.n. ]. Microtomographic models for all valid P ythiopina species, including the holotype of the newly described species, are presented and analysed. Endoskeleton morphology (specifically characters of the tentorium and metendosternite) proved to be informative at the specific and generic levels. An identification key is provided to all known species of the subtribe. Environmental niche models are presented for the majority of species. A molecular phylogeny of P edinini based on six genetic loci (28S : D 1–D 3 region; 28S : D 4–D 5 region, COII , A rgK , CAD 2, wg) was also produced to explore the phylogenetic position of P ythiopina. This analysis is the first to include representatives of all seven subtribes of P edinini, and supports a sister relationship between P ythiopina and the P alaearctic subtribe D endarina. Results also suggest the existence of a second pair of sister taxa within P edinini (in addition to M elambiina) with an amphitropical A frican distribution. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:285AD87A‐46B1‐4FE9‐BC57‐949EA1F70D49 .  相似文献   

15.
Nakano, T., Ramlah, Z. & Hikida, T. (2012). Phylogenetic position of gastrostomobdellid leeches (Hirudinida, Arhynchobdellida, Erpobdelliformes) and a new family for the genus Orobdella. —Zoologica Scripta, 41, 177–185. The leech family Gastrostomobdellidae is characterized by its possession of an agnathous and euthylaematous pharynx, a ventral gastropore and a gastroporal duct. In this study, the phylogenetic position of two gastrostomobdellid genera, Gastrostomobdella and Orobdella, was investigated using partial nucleic 18S, 28S rDNA and mitochondrial 12S rDNA sequences. Our phylogenetic analyses showed that both Gastrostomobdella and Orobdella are nested within Erpobdelliformes, but Gastrostomobdellidae is not a monophyletic taxon. Orobdella is a sister taxon of the other Erpobdelliformes taxa. The phylogenetic position of Gastrostomobdella within the clade of Gastrostomobdella, Erpobdellidae and Salifidae still remains uncertain. According to the reconstruction of the ancestral state of the pharynx in Erpobdelliformes, a euthylaematous pharynx is considered to be plesiomorphic in this taxon. Examination of Gastrostomobdella and Orobdella specimens indicates that the morphology of the gastroporal duct of Orobdella is quite different from that of Gastrostomobdella. A new family, Orobdellidae fam. nov., was therefore erected for the genus Orobdella. Orobdellidae is characterized by its possession of a generally tubular gastroporal duct, lying on the female organ.  相似文献   

16.
The pterolichoid feather mites of megapodes are reviewed. Named taxa are briefly discussed and most are figured. The Pterolichidae (Pterolichinae) are: Ascetohchus Perez & Atyeo, three species; Echinozonus Atyeo & Perez, six species; Pereziella Atyeo, two species; and Phycoferus Atyeo & Perez, two species. New pterolichine taxa, with the type species listed first, include: Botryaspis cordiforma gen. et sp.n. and B. cordata gen. et sp.n.; Cycloprotarsus lineatus gen. et sp.n., C. centralis gen. et sp.n. and C. monacrotrichus gen. et sp.n.; Eurypterolichus gen.n. for Pterolichus navicula comb.n. Trouessart & Neumann and E. coniger gen. et sp.n.; Goniodurus gen.n. for Pterolichus ( Pseudalloptes ) quadratus comb.n. Trouessart and G. bilobatus gen. et sp.n.; Haptepigynus gen.n. for Pterolichus ( Pseudalloptes ) tridentiger comb.n. Trouessart and H. holonotus gen. et sp.n.; Heliaspis ventralis gen. et sp.n.; Leipobius ocellatus gen. et sp.n.; Maleolichus maleo gen. et sp.n.; Mayracarus gen.n. for Pterolichus (P.) tritilobus comb.n. Trouessart; Megapodobius arcuatus gen. et sp.n. and M. striatus gen. et sp.n.; Oxygynurus brevissimus gen. et sp.n., O. longicaulis gen. et sp.n., O. mediocaulis gen. et sp.n. and O. parvicaulis gen. et sp. n.; Prionoturus amembranatus gen. et sp. n.; Talegallobius bidentatus gen. et sp.n.; and Tanysomacarus imperfectus gen. et sp.n. and T. brachymeles gen. et sp.n. A new taxon of the Thoracosathesidae is: Thoracosathes caudiculata sp.n. Keys are provided and host- commensal associations are discussed. All taxa are restricted to the Megapodiidae. Cheylabis fuscina Trouessart is assigned to Pereziella and has as a synonym P. dupilcata Atyeo.  相似文献   

17.
With the realization that new data (especially ultrastructural) and new ideas are making necessary a major revision of the scheme of classification of the Ciliophora, several groups of ciliatologists are preparing treatises on the subject. The present paper is concerned with the composition of the large new class of ciliates, Kinetofragmophora de Puytorac et al., 1974, established very recently by the French group. Several new taxa, at ordinal and subordinal levels, are proposed for inclusion in that class, with special emphasis on the new order to contain the most primitive of extant species. Actions taken here are incorporated in a major review and revisory work of the author which is being published elsewhere. The class Kinetofragmophora, by far the largest of the 3 classes now recognized as comprising the whole phylum Ciliophora, is itself considered to contain 4 sizeable subclasses and to embrace a total of 13 orders and 14 suborders. Two orders and 6 suborders are named and described here as new, enumerated and briefly identified as follows: Order Primociliatida n. ord., for the most “primitive” of gymnostomes, with three new suborders— Homokaryotina n. subord., for the homokaryotic genus Stephanopogon; Karyorelictina n. subord., for a number of mostly interstitial ciliates which, though heterokaryotic, possess nondividing, diploid macronuclei (e.g. Trachelocerca, Trachelonema, and Tracheloraphis); and Prorodontina n. subord., for a group of relatively specialized formerly “rhabdophorine” gymnostomes such as Coleps, Placus, and Prorodon and order Haptorida n. ord., for rapacious carnivorous forms, formerly lumped with the preceding groups as “rhabdophorines,” many with oral toxicysts and well developed thigmotactic ciliature (e.g. Actinobolina, Didinium, Dileptus, Enchelys, Spathidium, and Trachelius). All foregoing taxa are members of the 1st kinetofragmophoran subclass, the Gymnostomata. In the taxonomic conclusions drawn, new significance is placed on ultrastructural data, on macronuclear differences of evolutionary importance, and on habitat and behavior. A brief review of the literature on psammophilous ciliates is presented. In the subclass Vestibulifera is now located the order Entodiniomorphida Reichenow, a group formerly considered to be a spirotrich taxon. A suborder, Blepharocorythina n. subord., is proposed to contain the old “trichostome” family Blepharocorythidae, species commensalistic in horses and ruminants and now—with their syncilia, etc.—considered ancestral to the ophryoscolecids and relatives. In the subclass Hypostomata, order Nassulida, the suborder Paranassulina n. subord. is established to contain nassulids which appear more highly evolved than Nassula itself (e.g. Paranassula and Enneameron) in perioral ciliature, mode of stomatogenesis, etc. In the enigmatic and still vexatious order Rhynchodida, the suborder Aneistrocomina n. subord. is erected to embrace rhynchodid genera with an anteriorly located sucking tentacle (and other unique characteristics)—for example, Ancistrocoma, Crebricoma, Holocoma, and Sphenophrya. With the banishment of the bulk of the old “thigmotrichs” to the oligohymenophoran order Scuticociliatida, the ancistrocomines are left with the family Hypocomidae (and relatives) in the order Rhynchodida. It is not yet clear, however, how closely related the 2 suborders of rhynchodids should be considered. Special nomenclatural problems are also involved.  相似文献   

18.
Abstract: New multituberculate mammals from the Hauterivian/Barremian transition of Europe are described. They were found in the late Hauterivian‐early Barremian fossiliferous locality of La Cantalera (Josa, Teruel, Spain), one of the Early Cretaceous sites in the Aragonese branch of the Iberian Ranges, in northeastern Iberia. The fossils have been assigned to at least three taxa on the basis of nine isolated teeth: a new pinheirodontid taxon, Cantalera abadi gen. et sp. nov.; a representative of the eobaatarid Eobaatar; a taxon described as Plagiaulacidae or Eobaataridae gen. et sp. indet.; and other as Plagiaulacida indet. These fossils have increased the resolution of European Early Cretaceous multituberculate mammalian biostratigraphy and palaeobiogeography: the oldest representative of Eobaatar is described here; a taxon is assigned to ?Plagiaulacidae, in which case it would be the first of this family in the Iberian Peninsula; and the discovery of a new late Hauterivian pinheirodontid taxon demonstrates greater biodiversity and a wider distribution for these multituberculates than was previously known. The mutituberculate fauna of La Cantalera consists of endemic taxa (Pinheirodontidae), which were restricted to what is now Western Europe, and others (Eobaataridae) which have also been described in Asia. Consistent with the Iberian record of late Barremian gobiconodontid mammals, the presence of Eobaatar in Iberia with representatives from the late Hauterivian to late Barremian, as well as in the Aptian or Albian of Mongolia, indicates that faunal exchanges between Europe and Asia could have existed for most of the Early Cretaceous, either sporadically or constantly.  相似文献   

19.
The morphological and anatomical nature of perennating storage organs of the predominantly Australasian orchid tribe Diurideae (Orchidoideae: Orchidaceae) as well as anatomical concepts in tribes Orchideae and Diseae of Orchidoideae have been problematic for 150 yr, reflected in conflicting or vague terminology and questions about polystely and even monophyly of Orchidoideae. From a representative survey of underground organs of 145 species in 37 ingroup genera (Diurideae) and two outgroup genera (Spiranthes and Disa), the so-called “root-stem tuberoids” are here interpreted as root tubers (except for the stem tubers of Rhizanthella) borne on either droppers or stolonoid roots. All root tubers examined are bounded by a 1–4 layered velamen and exodermis, whereas droppers and stolonoid roots may have velamen-exodermis or a simple epidermis depending on the taxon and often bear multiseriate or uniseriate trichomes associated with mycorrhiza (as do roots of some taxa). The “polystely” reported in tubers of many Orchideae also occurs in tubers of many Diurideae but represents only dissection of the siphonostele into 2–13 traces. Cladistic analyses of data show extraordinarily high levels of homoplasy in characters related to root, dropper/stolonoid root, and tuber, so that these characters alone are of limited usefulness.  相似文献   

20.
Many taxon names in any classification will be composed of taxa that have yet to be demonstrated as monophyletic, that is, characterized by synapomorphies. Such taxa might be called aphyletic, the flotsam and jetsam in systematics, simply meaning they require taxonomic revision. The term aphyly is, however, the same as, if not identical to, Hennig's “Restkörper” and Bernardi's merophyly. None of these terms gained common usage. We outline Hennig's use of “Restkörper” and Bernardi's use of merophyly and compare it to aphyly. In our view, application of aphyly would avoid the oft made assumption that when a monophyletic group is discovered from within an already known and named taxon, then the species left behind are rendered paraphyletic. By identifying the flotsam and jetsam in systematics, we can focus on taxa in need of attention and avoid making phylogenetic faux pas with respect to their phylogenetic status.  相似文献   

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