PATTERNS OF EVOLUTION AND EXTINCTION IN THE LAST HARPETID TRILOBITES DURING THE LATE DEVONIAN (FRASNIAN)

Abstract: Late Devonian (Frasnian) harpetid trilobites have hitherto only been described from the western side of the Protethys Ocean, in what is now Europe and North Africa, as well as from Gondwana‐derived northwestern Kazakhstan (Mugodjar). However, late Frasnian strata in the Canning Basin, Western Australia, that were deposited on the eastern side of this ocean, contain a rich harpetid fauna. Described herein are two new harpetids: Eskoharpes gen. nov. and Globoharpes gen. nov., within which are placed six species: E. palanasus sp. nov., E. wandjina sp. nov., E. boltoni sp. nov., E. guthae sp. nov., G. teicherti sp. nov. and G. friendi sp. nov. The ontogenetic development of E. palanasus, E. wandjina and G. teicherti are described, including the first unequivocal harpetid protaspis. Globoharpes exhibits evidence of sexual dimorphism in the development of a pronounced preglabellar boss in some specimens. This structure is thought to have functioned as a brood pouch. Such structures have previously only been described in Cambrian and Ordovician trilobites, and never before in harpetids. It is suggested that the characteristic harpetid fringe functioned as a secondary respiratory structure. The Eskoharpes lineage shows evolutionary trends that mirror changes seen in ontogenetic development of the youngest species, suggesting the operation of peramorphic processes. This is the first record of heterochrony in harpetids and the first documented example of peramorphosis in Devonian trilobites. These harpetids demonstrate a stepped pattern of extinction during the late Frasnian, probably related to the effects of the two Kellwasser biocrises that have been well documented in European Frasnian sections. Highly vaulted species of Eskoharpes and the strongly vaulted Globoharpes became extinct at the Lower Kellwasser Event. The flatter species of Eskoharpes became extinct at the base of the Upper Kellwasser Event shortly prior to the Frasnian/Famennian boundary. The extinction of these harpetids, along with contemporaneous forms from Europe, which are also discussed herein, marks the end of the trilobite order Harpetida worldwide.     

Environmentally controlled phyletic evolution, blindness and extinction in Late Devonian tropidocoryphine trilobites

The Middle and Upper Devonian carbonate succession of the Montagne Noire, Southern France has been precisely zoned by an unbroken sequence of conodont zones. Stratigraphic control is excellent, and has allowed evolutionary changes in tropidocoryphine trilobites, which occur throughout the succession, to be directly established. The tropidocoryphine had been a stable group for some 40 million years prior to the Middle Givetian. In their last few million years, however, they underwent rapid evolution and exhibit some striking transformations of the cephalon and the regression and virtual disappearance of the eye within a relatively short space of time. They also show a marked diminution in size, and lose their original relief so that the glabella becomes virtually flush with the surface. There are two separate lineages, both of which show eye-reduction and subsequent blindness. In the earlier lineage Tropidocoryphe (Longicoryphe)-Erbenicoryphe, the main features of the ancestral rootstock are conserved and the stable, strongly divergent anterior sutural pattern of the cephalon remains the same. The eye, however, became reduced to a slightly convex surface lacking lenses, only indistinctly defined. Erbenicorphe is confined to well-oxygenated facies, and probably lived as a shallow burrower within the sediment; it became extinct in the early Frasnian. The second lineage T. (Longicoryphe)-Pterocoryphe- Pteroparia shows a remarkable backward migration of the suture, which progressively swings posteriorly in successive species spanning four Frasnian conodont zones (about three million years duration). At the same time the eye progressively degenerates so that the last forms are blind. Sutural migration and eye reduction are not genetically linked, however; the unusual form of the cephalon and suture probably resulted from an adaptation to the euxinic environment in which Pterocoryphe originated. The loss of the eye resulted from the adoption of an endobenthic habit in Pteroparia which descended from the ancestral Pterocoryphe but which had migrated to an oxygenated facies. Eye-reduction is therefore parallel in the two lineages, but superimposed upon a different original cephalic configuration. The last Pteroparia became extinct when the late Frasnian fauna became overwhelmed by the first pulse of the ‘Kellwasser Event’ (probably an anoxic overturn). The evolving characters, through virtually all observed steps, show progressive unidirectional change without sudden breaks or saltations. Such unidirectional evolution is an adaptive response to constant long-lasting environmental influences. □Evolution, Devonian trilobites, France, gradualism, eye reduction.     

New Eocene dinoflagellate cysts from the southern edge of the Junggar Basin,Xinjiang, China

The Anjihaihe Formation in the southern edge of the Junggar Basin was previously considered a series of freshwater lacustrine depositions. However, abundant marine dinoflagellate cysts were recently recovered from the middle to upper part of the middle member of the formation. Two new genera, six new species and one new subspecies among the abundant dinoflagellate cysts are described and illustrated, i.e. Circulodinium? laeve sp. nov., Kaiwaradinium abbreviatum sp. nov., Spiniferites adnatus subsp. latispinus subsp. nov., Oligosphaeropsis accreta gen. et. sp. nov., Oligosphaeropsis complex gen. et. sp. nov., Oligosphaeropsis megaprocessa gen. et. sp. nov. and Tianshandinium biconicum gen. et. sp. nov. They are rare to common constituents of the dinoflagellate assemblage in the Anjihaihe Formation and may prove useful for regional biostratigraphic correlation and palaeoenvironment re-establishment.     

First selenosteid placoderms from the eastern Anti‐Atlas of Morocco; osteology,phylogeny and palaeogeographical implications

Abstract: A new placoderm assemblage is reported from the Kellwasser facies of the eastern Anti‐Atlas, Morocco. This is the first record of an abundant Frasnian placoderm assemblage from Africa. The following new selenosteid taxa are described: Draconichthys elegans gen. et sp. nov., Enseosteus marocanensis sp. nov. and Walterosteus lelievrei sp. nov. In addition, material of Rhinosteus cf. parvulus is figured and described for the first time from Gondwana. The genera Enseosteus, Rhinosteus and Walterosteus are reviewed. ‘Wildungenichthys’ is regarded as a junior subjective synonym of Walterosteus. The new material and a revision of the taxa from Bad Wildungen, Germany, are the basis for a new phylogenetic analysis of the selenosteid arthrodires. The monophyly of the selenosteids is confirmed. The North American selenosteids are a sister group of Moroccan and European selenosteids, excluding Pachyosteus. The Moroccan vertebrate assemblage resembles that of Bad Wildungen. This supports the close palaeogeographical positions of Gondwana and Laurussia during the Late Devonian and indicates that biogeographical barriers for placoderms that could have separated the two assemblages were absent.     

Early Cretaceous non‐marine Ostracoda from the North Falkland Basin,South Atlantic

Twenty‐seven species of well‐preserved and abundant Early Cretaceous non‐marine ostracod crustaceans were recovered from the North Falkland Basin. The assemblage is unusually diverse for a non‐marine palaeoenvironment and is sourced from cuttings samples collected during 2011 drilling of wells by Desire and Rockhopper Exploration, in the northern and southern areas of the basin. Ostracoda are entirely undocumented in published accounts from this basin, and all but one species appear to be new to science. For the new taxa, one new family (Alloiocyprideidae; type genus Hourcqia) is proposed and includes Hourcqia woodi sp. nov. Four new genera are erected: Falklandicypris gen. nov.; type species F. petrasaltata sp. nov., Gangamoncythere gen. nov.; type species G. colini sp. nov., Paraplesiocypridea gen. nov.; type species P. alloios sp. nov., and Musacchiocythere gen nov.; type species M. sarunata (Musacchio, 1978 ). Nine other species are described as new and are Falklandicypris desiderata, Clinocypris epacrus, Cypria poietes, Ilhasina? leiodermatus, Looneyellopsis tuberculatus, Theriosynoecum petasmathylacus, Theriosynoecum ballentae, Timiriasevia fluitans, and Vecticypris samesi. The remainder are left in open nomenclature due to paucity of material. The ostracod assemblage is largely restricted to the southern part of the basin (wells 25/5‐1 and 26/6‐1). In the northern part of the basin only four species, dominated by Vecticypris samesi, are present and with one possible exception are restricted there. There appears to have been little or no interchange of species suggesting that a barrier probably existed between the northern and southern regions. The more diverse southern assemblage indicates that more favourable conditions existed to the south. Stratigraphically, a distinct change in faunal composition recorded in both southern wells is likely to be an isochronous event correlatable across the southern area, and of an age no younger than Hauterivian.     

The fate of the homoctenids (Tentaculitoidea) during the Frasnian–Famennian mass extinction (Late Devonian)

The homoctenids (Tentaculitoidea) are small, conical‐shelled marine animals that are among the most abundant and widespread of all Late Devonian fossils. They were a principal casualty of the Frasnian–Famennian (F‐F, Late Devonian) mass extinction, and thus provide an insight into the extinction dynamics. Despite their abundance during the Late Devonian, they have been largely neglected by extinction studies. A number of Frasnian–Famennian boundary sections have been studied, in Poland, Germany, France, and the USA. These sections have yielded homoctenids, which allow precise recognition of the timing of the mass extinction. It is clear that the homoctenids almost disappear from the fossil record during the latest Frasnian ‘Upper Kellwasser Event’. The coincident extinction of this pelagic group, and the widespread development of intense marine anoxia within the water column, provides a causal link between anoxia and the F‐F extinction. Most notable is the sudden demise of a group, which had been present in rock‐forming densities, during this anoxic event. One new species, belonging to Homoctenus is described, but is not formally named here.     

蒙古南戈壁泥盆纪(埃姆斯期-艾菲尔期)牙形刺

在蒙古南戈壁地区丘隆组(Chuluun Formation)和查干卡勒噶组(Tsagaankhaalga Formation)发现的牙形刺证明丘隆组的时代为晚埃姆斯期,查干卡勒噶组的时代为早艾菲尔期,与以前大化石所确定的时代一致。但艾菲尔阶的底界暂时还无法准确确定,蒙古南戈壁地区艾菲尔阶牙形刺动物群与同期北美的牙形刺动物群相似．但也包含一些地方性分子,蒙古海相艾菲尔期的沉积可能不完整。本文描述了2个命名新种．Caudicriodus delicatus sp. nov. , C. paraculicellus sp. nov. ,一个未命名新种,Caudicriodus sp. nov. A和一个新亚种,Cuadicriodus angustus cauda subsp, nov.。     

A new genus of Elateriform beetles (Coleoptera,Polyphaga) from the Jurassic of Daohugou,China

A new coleopteran genus, Parelateriformius, gen. nov., comprising the species P. communis, sp. nov., P. villosus, sp. nov., P. capitifossus, sp. nov., and P. mirabdominis, sp. nov., is described from Daohugou deposits, Inner Mongolia, China, and is assigned to the infraorder Elateriformia. The systematic position of the new genus within the suborder Polyphaga is discussed.     

New fossil mantidflies (Insecta: Neuroptera: Mantispidae) from the Mesozoic of north‐eastern China

Abstract:  Three new genera and four new species of the extinct mantidfly subfamily Mesomantispinae (Insecta: Neuroptera: Mantispidae) are described from the Lower Cretaceous Yixian Formation of Liaoning and the Middle Jurassic Jiulongshan Formation of Inner Mongolia: Archaeodrepanicus nuddsi gen. et sp. nov., A. acutus gen. et sp. nov., Sinomesomantispa microdentata gen. et sp. nov., (Yixian Formation) and Clavifemora rotundata gen. et sp. nov. (Jiulongshan Formation). The specimens described herein represent the first Mesozoic mantidfly compression fossils to have body parts preserved, including the specialized raptorial forelegs articulated to the prothorax anteriorly, an autapomorphy of the family. These new taxa further confirm the placement of the subfamily Mesomantispinae within the family Mantispidae; however, the monophyly of Mesomantispinae has not been confirmed, and it is likely that it will prove to be paraphyletic.     

Sedimentary and faunal changes across the frasnian/famennian boundary in the canning basin of Western Australia

The Canning Basin of northwestern Australia is a key area for understanding global changes at the “Kellwasser Events” and the Frasnian‐Famennian boundary. Frasnian stromatoporoid‐coral‐cyanobacterial reef platforms stretched out for enormous distances along the palaeoshelf but in the early Famennian they were completely replaced by cyanobacterial reef platforms. An iridium anomaly in the sequence was formerly believed to be at or close to the boundary and was interpreted as possible evidence for an asteroid impact. Recent field work and detailed biostratigraphy in the area east and southeast of Fitzroy Crossing has given dating relevant to the timing and extent of sea level changes, hypoxic incursions and reef backstepping. Goniatites and conodonts provide correlations with the international biostratigraphy.

In the Horse Spring area the stage boundary falls within the Virgin Hills Formation which normally has a rich pelagic goniatite, nautiloid and conodont fauna. In the latest Frasnian (Zone 13 of Klapper 1989; regional Sphaeromanticoceras lindneri Zone) large allochthonous reef blocks moved downslope into the open marine basin. A diverse gastropod fauna is associated with the last atrypid brachiopods. The faunal record at the immediate boundary is obscured by dolomitisation but manticoceratid goniatites range into this level. There is no evidence for the organic‐rich dark Kellwasser limestone facies.

In the McWhae Ridge area two Frasnian goniatite horizons with Beloceras trilobites and the giant Mamicoceras guppyi and Sphaeromanticoceras lindneri transgress over the reef slope. Stromatolitic cyanobacterial beds mark condensations. Again there is no trace of the oxygen‐depleted Kellwasser facies. However, as at Horse Spring, manticoceratids persisted into dolomitic marker beds that have no other preserved macrofauna. The iridium anomaly associated with Frutexites postdates the Frasnian‐Famennian boundary and was formed by cyanobacterial concentration.     

New mesozoic diving beetles (Coleoptera,Dytiscidae) from China

A new subfamily of predaceous diving beetles, Liadytiscinae subfam. nov., including two genera and four species, Liadytiscus gen. nov. (L. cretaceus sp. nov., L. longitibialis sp. nov., and L. latus sp. nov.) and Liadroporus gen. nov. (L. elegans sp. nov.), from the Late Tithonian-Berriasian (Huangbanjigou, Yixian Formation) of China is described. Two new genera, Mesoderus gen. nov. with two species, M. magnus sp. nov. and M. ventralis sp. nov., and Sinoporus gen. nov. with one species, S. lineatus sp. nov., are also described; their position in the system of Dytiscidae remains uncertain. Relationships of the taxa described with Recent and fossil taxa of the same rank and some presumable ecological features of the new taxa are discussed.     

New Upper Devonian Rhynchonellids (Brachiopoda) from Transcaucasia

Anew genus, Zezinia gen. nov., and two new species, Zezinia multicostata sp. nov. and Zaigunrostrum nakhichevanense sp. nov., are described from the Upper Devonian of Transcaucasia. The first genus is one of the last Frasnian representatives of the family Uncinulidae. The Famennian Z. nakhichevanense sp. nov. belongs to punctate rhynchonellids of the family Trigonirhynchiidae.     

Dinoflagellate cyst biostratigraphy of the Coniacian–Santonian (Upper Cretaceous): New data from the English Chalk

Results are presented here for the first chalk-based, high-resolution quantitative study of organic-walled dinoflagellate cysts (dinocysts) from the entire Coniacian–Santonian Chalk successions in east Kent and on the Isle of Wight. The lithostratigraphy and dinocyst records (137 taxa) of seven sections are presented, and the stratigraphic ranges of taxa are constrained relative to stage and zonal boundaries, located using extensive macrofossil data. Results are integrated with a previous complementary study of the Isle of Wight Santonian to test and refine existing dinocyst bioevent schemes. Sixteen dinocyst events are proposed as a sequence of biostratigraphic datum levels for the lower Coniacian to uppermost Santonian which, based on average sedimentation rates, represent an average temporal resolution of around 360 kyr. The event stratigraphy forms a basis for the first high-resolution correlation study of quantitative dinocyst data from the Upper Cretaceous of NW Europe. A new genus Culversphaera Prince, Jarvis, Pearce et Tocher gen. nov. is proposed with the new combination Culversphaera velata Prince, Jarvis, Pearce et Tocher gen. et comb. nov. Five new species: Ellipsodinium membraniferum Prince, Jarvis, Pearce et Tocher sp. nov., Senoniasphaera macroreticulata Prince, Jarvis, Pearce et Tocher sp. nov., Senoniasphaera whitenessii Prince, Jarvis, Pearce et Tocher sp. nov., Xenascus spinatus Prince, Jarvis, Pearce et Tocher sp. nov. and X. yunii sp. nov., and the new subspecies S. protrusa congrensa Prince, Jarvis, Pearce et Tocher subsp. nov. are described.     

A new subfamily of ichneumon wasps (Insecta: Hymenoptera: Ichneumonidae) from the Upper Cretaceous of the Russian Far East

A new subfamily of ichneumon wasps, Labenopimplinae subfam. nov. (Ichneumonidae), is described from the Cenomanian Ola Formation of the locality Obeshchayushchiy, Magadan Region, Russian Far East. The subfamily is highly diverse morphologically and combines characters of the Labeninae and Pimplinae. It includes 11 new species described in five new genera: Labenopimpla rasnitsyni gen. et sp. nov., L. kasparyani sp. nov., Armanopimpla zherikhini gen. et sp. nov, Ramulimonstrum intermedium gen. et sp. nov., Rugopimpla vulgaris gen. et sp. nov., R. fallax sp. nov., R. angusticella sp. nov., R. macra sp. nov., R. matrona sp. nov., Micropimpla lucida gen. et sp. nov., and M. obscura sp. nov. Also described is a new monotypic genus, Tryphopimpla xoridoptera gen. et sp. nov., which combines characters of the Tryphoninae, Pimplinae, and Xoridinae and cannot be currently placed into any of the known subfamilies. The population of fossil ichneumon wasps at this locality is distinctly dominated by females.     

EXCEPTIONALLY WELL-PRESERVED MIDDLE ORDOVICIAN SPONGES FROM THE LLANDEGLEY ROCKS LAGERSTÄTTE, WALES

Abstract:  A diverse fauna of three-dimensionally preserved sponges is described from nearshore volcanogenic sandstones near Llandrindod, Mid-Wales. The fauna was preserved through early marginal silicification, in rare examples with silicification of soft tissue, and includes aspicular and spicular demosponges, hexactinellids, and a heteractinid. The fauna is largely endemic, with the following new species, genera and families erected: Onerosiconcha gregalia gen. et sp. nov., Ordinisabulo quadragintaforma gen. et sp. nov., Miritubus erinaceus gen. et sp. nov., Vadosifistula milvus gen. et sp. nov., Polycornua trescelestus gen. et sp. nov. (Pseudolanciculidae fam. nov.), P. entropus sp. nov., Palaeocallyoides improbabilis gen. et sp. nov., Reticulicymbalum tres gen. et sp. nov., Triactinella rigbyi gen. et sp. nov. (Triactinellidae, fam. nov.), Spissiparies minuta gen. nov., Brevicirrus arenaceus gen. et sp. nov., Pyritonema scopula sp. nov. (Pyritonemidae, fam. nov.) and Microastraeum tenuis gen. et sp. nov. In addition, Pseudolancicula Webby and Trotter is recorded outside Australia for the first time, although only as isolated spicules. The environment represented by this fauna has not previously yielded articulated sponges, and thus the apparent endemism may be misleading.     

Upper Devonian Sponges from the Holy Cross Mountains, Central Poland

The rich fauna of Late Devonian (Late Frasnian) siliceous sponges from the Holy Cross Mountains, Poland is composed of 15 species and 11 genera. Both astylospongid demosponges (lithistids) and hexactinosan hexactinellids are present. The following new genera and/or species are proposed: D regulara Rigby and Pisera sp. nov., Jazwicella media Rigby and Pisera gen. et sp. nov., Astyloscyphia irregularia Rigby and Pisera gen. et sp. nov., A. turbinata Rigby and Pisera gen. et sp. nov., Astylotuba modica Rigby and Pisera gen. et sp. nov., Paleoregulara cupula Rigby and Pisera gen. et sp. nov., Paleoramospongia bifurcata Rigby and Pisera gen. et sp. nov., Cordiospongia conica Rigby and Pisera gen. et sp. nov., Paleocraticularia elongata Rigby and Pisera gen. et sp. nov., P gigantia Rigby and Pisera gen. et sp. nov., Polonospongiadevonica Rigby and Pisera gen. et sp. nov., P fistulata Rigby and Pisera gen. et sp. nov., Urnospongia modica Rigby and Pisera gen. et sp. nov., and Conicospongia annulata Rigby and Pisera gen. et sp. nov. The investigated fauna contains the youngest astylospongiids known and the oldest well-preserved, and most diversified Palaeozoic hexactinosans. The sponge fauna constituted a significant element of a brachiopod-coral-sponge assemblage that inhabited a deep slope of the local Dyminy Reef structure, during its final phase of growth, in a clearly hemipelagic setting. This fauna is limited to the intrashelf depression within an incipiently drowned carbonate platform.     

New planthoppers of the tribe Achilini (Homoptera,Fulgoroidea, Achilidae) from Baltic amber

New taxa of Achilini (Achilidae) are described from Baltic amber: Paratesum rasnitsyni gen. et sp. nov., Protomenocria notata gen. et sp. nov., Psycheona variegata gen. et sp. nov., P. striata sp. nov. Protepiptera kaweckii Usinger, 1939 (= Cixidia christinae Lefebvre, Bourgoin et Nel, 2007, syn. nov.) is redescribed with designation of a neotype. “Cixius” testudinarius Germar et Berendt, 1856, “C.” longirostris Germar et Berendt, 1856 and “Oliarus” oligocenus Cockerell, 1910 are transferred to Achilini. A key to the genera of Achilidae known from Baltic amber is provided.     

Heterobranchia (Gastropoda) from the Jurassic Deposits of Russia

Small gastropods from the Jurassic deposits of the European Russia, united into the lower Heterobranchia or Allogastropoda, are described. The families of Ampezzanildidae, Cimidae, Cornirostridae, Ebalidae, and Stuoraxidae are distinguished, and a set of taxa is given without reference to a definite family. The family Ampezzanildidae from the Jurassic deposits is described for the first time on the basis of the mass material, ascribed to the new genus Zizipupa gen. nov. with the sole species of Z. costata sp. nov. The family Cimidae includes the genera of Cristalloella, Rotfanella, Urlocella, and Unzhispira gen. nov. with species C. spiralocostata (Gründel, 1998), R. gerasimovi sp. nov., R. reticulata sp. nov., Urlocella undulata sp. nov., and Unzhispira minuta sp. nov. The genus Heteronatica gen. nov. is included into the family Cornirostridae. This genus is the first siphonostomatous representative of the given family including the sole long-living species H. globosa sp. nov., which is subdivided into subspecies H. globosa globosa and H. globosapromota subsp. nov. The family Ebalidae is represented by the genus Ebala, shells of which are distributed from the Middle Oxfordian to the Middle Volgian. The family Stuoraxidae is described based on two genera Stuoraxis and Aneudaronia gen. nov., including species of S. crassa sp. nov. and A. elegans sp. nov. The genus Doggerostra, which fits into different families of Heterobranchia in terms of shell morphology is represented by the species D. riedeli Gründel, 1998, which was previously known from the Bathonian and Callowian deposits in Poland and Germany, as well as form the Upper Jurassic interval in the Russian Plate. The Middle Volgian subspecies D. riedeli affinis subsp. nov. is distinguished in the composition of this species. In addition, the genus Masaevia gen. nov. with the sole species of M. sinistra sp. nov. is described. Due to so specific shell morphology of this genus, its position in the Heterobranchia system is unclear. It is not improbable that we deal with small planktonic gastropods of protoconchs of unknown group of planktonic or benthic gastropods.     

NEW CLADID AND FLEXIBLE CRINOIDS FROM THE MISSISSIPPIAN (TOURNAISIAN, IVORIAN) OF ENGLAND AND WALES

Abstract:  The modern study of fossil crinoids began with J. S. Miller who, in 1821, described specimens from southern England, nearby Wales and other regions, and named several common Early Carboniferous genera. Later, in 1950–60, James Wright monographed all known Early Carboniferous crinoids from the British Isles. In spite of such previous scrutiny, we recognize here two new genera among species already described: Glamorganocrinus gen. nov. (type species: Ophiurocrinus gowerensis Wright, 1960) from South Wales and Mendipocrinus gen. nov. (type species: Poteriocrinus latifrons Austin and Austin, 1847) from southern England. These new genera increase the number of advanced cladid genera in the Ivorian Substage of the Tournaisian in western Europe to 18, and the total number of crinoid genera to 36. A review of species assigned to Mespilocrinus has led to the recognition of M. granulifer De Koninck and LeHon, 1854 as a nomen dubium. A new species of Mespilocrinus , M. wrighti sp. nov., is described from the Ivorian of South Wales; this is the most highly derived species of the genus, as based on a phylogenetic analysis including ten species and 13 characters, with Pycnosaccus as the outgroup. A single, well-ordered tree resulted from this analysis. Interpretation of this tree suggests that the centre of evolution for Mespilocrinus was North America, where three species appeared during the Kinderhookian (early Tournaisian), rapidly achieving morphological disparity within the genus. This radiation event was part of the overall explosive radiation of crinoids following the Late Devonian mass extinction event when crinoid diversity was at a global minimum during the Frasnian. Recovery began during the Famennian, followed by an explosive radiation in the Tournaisian.     

A Remarkable New Family of Jurassic Insects (Neuroptera) with Primitive Wing Venation and Its Phylogenetic Position in Neuropterida

Background

Lacewings (insect order Neuroptera), known in the fossil record since the Early Permian, were most diverse in the Mesozoic. A dramatic variety of forms ranged in that time from large butterfly-like Kalligrammatidae to minute two-winged Dipteromantispidae.

Principal Findings

We describe the intriguing new neuropteran family Parakseneuridae fam. nov. with three new genera and 15 new species from the Middle Jurassic of Daohugou (Inner Mongolia, China) and the Early/Middle Jurassic of Sai-Sagul (Kyrgyzstan): Parakseneura undula gen. et sp. nov., P. albomacula gen. et sp. nov., P. curvivenis gen. et sp. nov., P. nigromacula gen. et sp. nov., P. nigrolinea gen. et sp. nov., P. albadelta gen. et sp. nov., P. cavomaculata gen. et sp. nov., P. inflata gen. et sp. nov., P. metallica gen. et sp. nov., P. emarginata gen. et sp. nov., P. directa gen. et sp. nov., Pseudorapisma jurassicum gen. et sp. nov., P. angustipenne gen. et sp. nov., P. maculatum gen. et sp. nov. (Daohugou); Shuraboneura ovata gen. et sp. nov. (Sai-Sagul). The family comprises large neuropterans with most primitive wing venation in the order indicated by the presence of ScA and AA1+2, and the dichotomous branching of MP, CuA, CuP, AA3+4, AP1+2. The phylogenetic position of Parakseneuridae was investigated using a phylogenetic analysis of morphological scoring for 33 families of extinct and extant Neuropterida combined with DNA sequence data for representatives of all extant families. Parakseneuridae were recovered in a clade with Osmylopsychopidae, Prohemerobiidae, and Ithonidae.

Conclusions/Significance

The presence of the presumed AA1+2 in wings of Parakseneuridae is a unique plesiomorphic condition hitherto unknown in Neuropterida, the clade comprising Neuroptera, Megaloptera, Raphidioptera. The relative uncertainty of phylogenetic position of Parakseneuridae and the majority of other families of Neuroptera reflects deficient paleontological data, especially from critical important periods for the order, earliest Triassic and latest Triassic/earliest Jurassic.