Julien Denayer

A complete insect from the Late Devonian period

After terrestrialization, the diversification of arthropods and vertebrates is thought to have occurred in two distinct phases, the first between the Silurian and the Frasnian stages (Late Devonian period) (425–385 million years (Myr) ago), and the second characterized by the emergence of numerous new major taxa, during the Late Carboniferous period (after 345 Myr ago). These two diversification periods bracket the depauperate vertebrate Romer’s gap (360–345 Myr ago) and arthropod gap (385–325 Myr ago), which could be due to preservational artefact. Although a recent molecular dating has given an age of 390 Myr for the Holometabola, the record of hexapods during the Early–Middle Devonian (411.5–391 Myr ago, Pragian to Givetian stages) is exceptionally sparse and based on fragmentary remains, which hinders the timing of this diversification. Indeed, although Devonian Archaeognatha are problematic, the Pragian of Scotland has given some Collembola and the incomplete insect Rhyniognatha, with its diagnostic dicondylic, metapterygotan mandibles. The oldest, definitively winged insects are from the Serpukhovian stage (latest Early Carboniferous period). Here we report the first complete Late Devonian insect, which was probably a terrestrial species. Its ‘orthopteroid’ mandibles are of an omnivorous type, clearly not modified for a solely carnivorous diet. This discovery narrows the 45-Myr gap in the fossil record of Hexapoda, and demonstrates further a first Devonian phase of diversification for the Hexapoda, as in vertebrates, and suggests that the Pterygota diversified before and during Romer’s gap.

Garrouste et al. reply

replying to T. Hörnschemeyer et al. Nature 494, 10.1038/nature11887 (2013)Since the nineteenth century, Devonian insects have repeatedly proven to be something else, the sole exception being Rhyniognatha. Recently the Devonian insect Strudiella devonica has been denied by Hörnschemeyer et al., who could not “confirm the presence of a mandible or of mandibular teeth”.

Stratigraphy and depositional environments of the Late Famennian (Late Devonian) of Southern Belgium and characterization of the Strud locality

The Famennian (Upper Devonian, c . 372 to 359 Ma) strata of Belgium have recently received much attention after the discoveries of early tetrapod remains and outstandingly preserved continental arthropods. The Strud locality has yielded a diverse flora and fauna including seed-plants, tetrapods, various placoderm, actinopterygian, acanthodian and sarcopterygian fishes, crustaceans (anostracans, notostracans, conchostracans and decapods) and a putative complete insect. This fossil assemblage is one of the oldest continental – probably fresh-water – ecosystems with a considerable vertebrate and invertebrate diversity. The study of the palaeoenvironment of the Strud locality is crucial because it records one of the earliest and most important phases of tetrapod evolution that took place after their emergence but before their terrestrialization. It raises the question of environmental and ecological conditions for the Devonian aquatic ecosystem and the selection pressures occurring at the onset of tetrapod terrestrialization. The present study characterized the fluvial facies of the Upper Famennian sedimentary rocks of Strud and the surrounding areas. The exceptional preservation of arthropods and plants in the main fossiliferous layers is explained by rapid burial in the fine-grained sediment of the quiet and confined flood plain environment. Newly investigated fossiliferous sections in the Meuse–Samson area led to the description and correlation of key sections (Strud, Wierde and Jausse sections, complemented by the less continuous Haltinne, Huy and Coutisse sections). Moreover, the investigated sections allowed a review of the age of the fossiliferous horizon, which is now definitely considered to be Late Famennian in age.

Rugose Corals Across the Devonian—Carboniferous Boundary in NW Turkey

An uppermost Famennian (Strunian) coral assemblage has been recovered in the middle part of the Yılanlı Formation of the Istanbul Zone (Zonguldak and Bartın areas, NW Turkey). In the Bartın area, the studied fossiliferous interval corresponds to a c. 30 m-thick unit of bioclastic to peloidal wackestone to packstone grading to grainstone and including two stromatoporoid biostromes. In the Zonguldak area, 60 km westward, the bioclastic facies is dominant. The rugose corals are mainly solitary taxa belonging to the genera Campophyllum, Bounophyllum, Amplexocarinia, and ?Metriophyllum, and only one colonial genus occurs: Pseudoendophyllum. This fauna is similar to that documented in Europe. The campophyllids and dibunophyllids are the main component of the uppermost Famennian assemblages in S Belgium, N France, W Germany, NW and S Poland. The endophyllids occur in S Poland, Novaya Zemlya, and in the Ural Mountains. The Istanbul Zone is supposed to be situated in the central part of the Palaeotethys Ocean, along the southern margin of Laurussia during the uppermost Devonian and Carboniferous. The rugose corals indicate some relationship with the eastern part of Laurussia, or that both areas were under a common marine influence at this time. The global Hangenberg event was not recognized in the Turkish localities, except for the disappearance of the corals, occurring less than 19 m below the Devonian—Carboniferous boundary based on the foraminifers. There is no major facies change through the boundary and the first Carboniferous corals (small Uralinia and Caninophyllum) appear 6 m above the D–C boundary. The new species Caninophyllum charli sp. nov. is described from the upper part of the lower Tournaisian.

Cionodendron and related lithostrotionid genera from the Mississippian of eastern Australia: systematics, stratigraphy and evolution

Denayer, J. & Webb, G.E., 26.2.2015. Cionodendron and related lithostrotionid genera from the Mississippian of eastern Australia: systematics, stratigraphy and evolution. Alcheringa 39, xxx–xxx. ISSN 0311-5518. The Mississippian colonial rugose corals of eastern Australia are taxonomically reviewed and assigned to formal genera. Their homeomorphy with the Eurasian genera Siphonodendron and Lithostrotion but also Heterostrotion resulted from parallel evolution within the Lithostrotionidae. Fasciculate species are reassigned to Cionodendron, as they share a robust columella, septotheca and two series of tabellae. Based on common characters, three species groups are recognized: the C. columen Group (characterized by the occurrence of parricidal and non-parricidal increase), the C. hallense Group (development of second-order lonsdaleoid dissepiments) and the C. arundineum Group (lacking the previous characters). Fourteen species are recognized, one being new (C. smithi sp. nov.) and two documented for the first time in the area. The oldest species are late Tournaisian in age, but the genus is most diverse in the middle–late Visean. Several morphological lineages are recognized within the three groups. The massive species are classified in the newly erected genus Australastraea that likely evolved from one of the early species of Cionodendron in the early Visean. Eleven species were identified, two being newly described (A. arcifera, sp. nov., A. carinata sp. nov.) and two others documented for the first time. Australastraea is characterized by a septotheca that is commonly discontinuous, conferring a pseudo-cerioid or astreoid habit. Two morphological groups are identified: the A. wilkinsoni Group (small corallites with simple narrow dissepimentarium) and the A. columnare Group (large corallites with complex dissepimentarium). The small fasciculate species previously referred to Lithostrotion williamsi are here reassigned to the new genus Pickettodendron, which differs from Cionodendron by the lack of minor septa and presence of a complete tabularium but is, nevertheless, relatively closely related to that genus. Pickettodendron is represented by three species, one being new (P. nudum sp. nov.), and is restricted to the early (–‘middle’) Tournaisian. A polyphyletic origin of the Cionodendroninae is considered, with Cionodendron and Australastraea originated in a first species of Amygdalophyllum and Pickettodendron originated in a second one. The biostratigraphic value of the Cionodendroninae is currently limited owing to the poor stratigraphic coverage of appropriate facies but correlations were made possible by the identification of A. columellaris and C. consanguineum in the early Visean of New South Wales and Queensland, and A. columnare and A. sp. in the middle–late Visean of both states. The Cionodendroninae assemblages of eastern Australia are strongly endemic and possibly represent one of the scarce remains of the Panthalassa Province. Julien Denayer [julien.denayer@ulg.ac.be], Evolution and Diversity Dynamics Lab, Geology Department, University of Liège, B18, Allée du Six-Août, Sart Tilman, B-4000 Liège, Belgium; Gregory E. Webb [g.webb@uq.edu.au], Integrated Palaeoenvironmental Research Group, School of Earth Sciences, University of Queensland, QLD 4072, St-Lucia, Australia.

Earliest Mississippian rugose corals of eastern Australia: post-disaster fauna across the Devonian-Carboniferous boundary?

The most earliest Mississippian rugose corals are post-disaster taxa occurring in a biosphere strongly modified by the crises associated with the Devonian-Carboniferous Boundary. In Western Europe, basal Tournaisian rugose corals belong to the genera Conilophyllum, Hebukophyllum and Kizilia. Conilophyllum and Hebukophyllum are either homeomorphs or close relatives of each other and are likely post-disaster fauna showing wide morphological plasticity but with an unknown origin. Kizilia is a Lazzarus taxon, known also from basal Tournaisian strata of China, that suddenly reappeared at the Devonian-Carboniferous Boundary being related to the mid-Devonian stringophyllids. The deeper basinal facies of Western Europe (Montagne Noire, Rhenish Mts, Thuringia, Upper Franconia) yield mostly small non-dissepimented solitary rugose corals, together with some dissempimented ones, amongst which are mostly long-ranging taxa. In N America, Vesiculophyllum, a genus very similar, and probably related, to Kizilia occurs together with non-dissepimented long-ranging corals. Like most of the basal Tournaisian dissepimented rugose corals, Cystodactylon orbum gen. et sp. nov. and Gudmania darumbalae gen. et sp. nov. from the basal Tournaisian of eastern Australia are interpreted as post-disaster fauna. Their origin is not understood to date and they seemingly left no descent in the Carboniferous. Their stratigraphic range is extremely limited as they so far are known only in small reefs at the base of the lower Tournaisian Gudman Formation in the type area.

UPPER FRASNIAN (UPPER DEVONIAN) BRYOZOANS IN PROXIMAL FACIES OF SOUTHERN BELGIUM

Seven bryozoan species are described from the shallow-water Aisemont and Lambermont formations (upper rhenana Conodont zone, upper Frasnian) in southern Belgium. The studied interval is situated between the lower and upper Kellwasser events. Among the recognized taxa two species are new: Triznotrypa potii n. sp. and Isostylus veserensis n. sp. In addition, the following species were identified in this assemblage: Fistulipora pavimenta Bigey, 1988, Canutrypa hemispheroidea (Yang, 1954), Eostenopora conspersa Volkova, 1974, Leptotrypella radiata Bigey, 1988, and Anastomopora inflata (Bigey, 1988). The studied bryozoan assemblage of the Frasnian age shows palaeogeographic connections to Iran, Russia (Altai) and Afghanistan. Most of them are documented for the first time in this area and it provides important knowledge of the distribution of bryozoans in the late Frasnian and near the Frasnian-Famennian boundary.

Taxonomy, Biostratigraphy and Palaeobiogeography of the Late Tournaisian rugose corals of north-western Turkey

This article provides the first taxonomic description of Ivorian (Late Tournaisian, Early Carboniferous) rugose coral associations from north-western Turkey (Zonguldak and Bartın). Eleven species belonging to ten genera are described, one species is new. Three biostratigraphic assemblages are recognized. The oldest assemblage includes Cyathaxonia cornu, Cyathoclisia uralensis, ‘Lophophyllum’ konincki and Uralinia multiplex. This corresponds to the RC3 Biozone (early Ivorian). The middle assemblage in characterised by Amplexus coralloides, Sychnoelasma hawbankense and Zaphriphyllum daleki sp. nov. and is correlated with the early late Ivorian RC4α Biozone. The youngest assemblage (RC4β1 Biozone, latest Ivorian) is composed of Corphalia fourmarieri, Corphalia sp. and Amydgalophyllum? sp. These three assemblages have a low specific and generic diversity compared to time-equivalent assemblages but contain genera with a wide distribution in the Palaeotethys Ocean, such as Cyathoclisia, Uralinia and—in a lesser extend—Zaphriphyllum, as well as typically European taxa such as Corphalia and Sychnoelasma. These latter two, identified for the first time outside of Europe, allow associating north-western Turkey with the European Coral Province.KurzfassungDiese Arbeit präsentiert die ersten taxonomischen Beschreibungen von Assoziationen rugoser Korallen aus dem Ivorium (spätes Tournais, Unterkarbon) aus dem Nordwesten der Türkei (Zonguldak und Bartin). Es werden insgesamt elf Arten in zehn Gattungen beschrieben; eine der Arten ist neu. Drei biostratigraphische Assoziationen werden unterschieden. Die älteste beinhaltet die Arten Cyathaxonia cornu, Cyathoclisia uralensis, ‘Lophophyllum’ konincki und Uralinia multiplex. Dies entspricht der RC3 Biozone (frühes Ivorium). Die mittlere Assoziation wird durch Amplexus coralloides, Sychnoelasma hawbankense und Zaphriphyllum daleki sp. nov. Charakterisiert und wird mit der früh-spätivorischen RC4α Biozone korreliert. Die jüngste Vergesellschaftung (RC4β1 Biozone, spätestes Ivorium) beinhaltet die Taxa Corphalia fourmarieri, Corphalia sp. and Amydgalophyllum? sp. Diese drei Assoziationen haben eine niedrige Arten- und Gattungen-Diversität, im Vergleich mit anderen, gleichalten. Vergesellschaftungen, aber beinhalten Gattungen, die zu jener Zeit eine weite Verbreitung in der Paläotethys hatte, wie etwa Cyathoclisia, Uralinia und - in geringerem Maße - Zaphriphyllum. Daneben kommen typische europäische Taxa vor, wie Corphalia und Sychnoelasma. Diese beiden Gattungen, die hier zum ersten Mal außerhalb Europas identifiziert werden, erlauben es, das Ivorium der nordwestlichen Türkei mit der europäischen Korallen-Provinz zu assoziieren.

Late Devonian (Frasnian) phyllopod and phyllocarid crustacean shields from Belgium reinterpreted as ammonoid anaptychi

The taxonomic affinities of fossils from the Frasnian succession of Belgium previously described as phyllopod and phyllocarid crustacean shields are discussed. The rediscovery of the holotype of Ellipsocaris dewalquei, the type species of the genus Ellipsocaris Woodward in Dewalque, 1882, allows to end the discussion on the taxonomic assignation of the genus Ellipsocaris. It is removed from the phyllopod crustaceans as interpreted originally and considered here as an ammonoid anaptychus. Furthermore, it is considered to be a junior synonym of the genus Sidetes Giebel, 1847. Similarly, Van Straelen’s (1933) lower to middle Frasnian record Spathiocaris chagrinensis Ruedemann, 1916, is also an ammonoid anaptychus. Although ammonoids can be relatively frequent in some Frasnian horizons of Belgium, anaptychi remain particularly scarce and the attribution to the present material to peculiar ammonoid species is not possible.

Devonian to Basal Permian Lithostratigraphy in Southwestern Hakkari: A Perspective from Northern Arabian Mixed Carbonate–Siliciclastic Platform

The Middle Devonian-Lower Carboniferous succession in the Amanos Mountains to the west and in the Hakkari area to the east of the Hazro High are known as the Zap Group, divided into the Yiginli (Middle-Late Devonian) and Köprülü formations (Late Devonian-Early Carboniferous). The Group is overlain by the Late Permian Gomaniibrik Formation. The thickness of the Yiginli Formation, in the HakkariÇukurca area, ranges between 200 and 300 m. The vertebrate and microflora remains indicate a Famennian age for the top of the Yiginli Formation. Brachiopod samples recently collected from the Zap River Valley area allow to establish an Upper Givetian age for the upper middle part of the Yiginli Formation which was until now considered as Famennian on the basis of its micropaleontological contents. In particular, the presence of Atrypids excludes an age younger than Lower Frasnian. Studied brachiopods come from shell concentrations of various clayey-silty levels. The Köprülü Formation represents a variety of marine environments ranging from agitated shallow marine to muddy shelf conditions – below fair weather wave base – and then a return to more restricted shallow marine facies in the upper part. The Köprülü Formation was measured and investigated along the Zap 1 and Zap 2 sections located on the north-east of Köprülü village, 8 km northwest of Cukurca. The Köprülü Formation can be subdivided into three new members. The lower member is composed of dark to grayish limestone and sandy limestone representing the transgressive phase covering the continental deposits of the Yiginli Fomation. The corals described here were collected in this member. The coral assemblage is mainly composed of small non-dissepimented solitary corals belonging to the genera Rotiphyllum, Zaphrentites, cf. Gorizdronia, gen. et sp. indet. and Amplexizaphrentis, including a new species, A. zapense, and the dissepimented coral Caninia aff. cornucopiae. The middle member is composed of thinly laminated dark grey calcareous shales and siltstones; several sandstone layers are also intercalated. The upper part of this middle member is characterized by carbonate concretions embedded in sandy limestone. The fossils, including bivalves are well preserved in this member. The myalinid bivalves, with a few posidonid bivalves have been observed in dark grey calcareous shale horizons. The upper member is dominated by massive grayish sandy/dolomitic limestone with some dark shale intercalations.