Development of the graptoloid rhabdosome

Proximal development of the dichograptoid rhabdosome is re-examined in detail. Two major types are recognised: the artus type (= dichograptid type of Bulman) in which th 1¹ is dicalycal, and the isograptid type (= isograptid + leptograptid types of Bulman) in which theca 1² is dicalycal. In branching dichograptids, distal stipe division takes place by replication of the thecal budding sequence employed in the initial dichotomy of the rhabdosome and is always of isograptid type. Dichotomies beyond the first are unknown in species with initial development of other than isograptid type. The thecal budding pattern and stipe composition of dendroids can be interpreted in terms of the structure of, and thecal notation used for, graptoloids and it is thus possible to compare directly the mode of stipe division in the two groups. It is found that both distal and proximal dichotomy in dendroids are achieved by a pattern of thecal budding closely comparable with that of the isograptid type of division in graptoloids. The isograptid development type is therefore thought to have been directly derived from dendroids, and is the primitive type for Graptoloidea. The artus type was derived via three or more independent lineages, at least one of which (that leading to the artus group of pendent didymograptids) involved an ancestor with isograptid development. Proximal end characters of Phyllograptus suggest that this genus and biserial graptolites of the family Diplograptidae shared a common ancestor.     

The sthenurine affinity of the Late Miocene kangaroo,Hadronomas puckridgi Woodburne (Marsupialia,Macropodidae)

Previous studies of the dentition and cranial base of Hadronomas puckridgi Woodburne suggested that this large, Late Miocene kangaroo might be related to the Sthenurinae. A recently recovered specimen, in which the neurocranium, rostrum and some of the incisors are preserved, reveals a more definite affinity with the sthenurines in its possession of laterally expanded postorbital crests of the frontals, reduced I² accompanied by enlarged I³, the presence of a well-developed posterior mental foramen, a deep, posteriorly situated digastric eminence and elevated pterygoid fossa of the dentary.     

The architecture of Permian glossopterid ovuliferous reproductive organs

McLoughlin, S. & Prevec, R. 20 September 2019. The architecture of Permian glossopterid ovuliferous reproductive organs. Alcheringa XX, xxx–xxx. ISSN 0311-5518

A historical account of research on glossopterid ovuliferous reproductive structures reveals starkly contrasting interpretations of their architecture and homologies from the earliest investigations. The diversity of interpretations has led to the establishment of a multitude of genera for these fossil organs, many of the taxa being synonymous. We identify a need for taxonomic revision of these genera to clearly demarcate taxa before they can be used effectively as palaeobiogeographic or biostratigraphic indices. Our assessment of fructification features based on extensive studies of adpression and permineralized fossils reveals that many of the character states for glossopterids used in previous phylogenetic analyses are erroneous. We interpret glossopterid fertiligers to have been borne in loose strobili in which individual polysperms represent fertile cladodes of diverse morphologies subtended by a vegetative leaf or bract. Polysperms within the group are variously branched or condensed with ovule placement ranging from marginal to abaxial, in some cases occurring on recurved branchlets or in cupule-like structures. Glossopterid polysperms of all types are fringed by one or two ranks of wing-like structures that may represent the remnants of megasporophylls that were, ancestrally, developed on the fertile axillary shoot. Glossopterid fertiligers have similarities to the condensed bract/ovuliferous scale complexes of conifer cones, but comparisons with Mesozoic seed-ferns are hindered by insufficient data on the arrangement and homologies of the ovule-bearing organs of the latter group. Nevertheless, glossopterid polysperms differ from the ovuliferous organs of Mesozoic seed-ferns by longitudinal versus transverse folding, respectively.

Stephen McLoughlin* [steve.mcloughlin@nrm.se], Department of Palaeobiology, Swedish Museum of Natural History, Box 50007, 104 05 Stockholm, Sweden; Rose Prevec [r.prevec@am.org.za], Department of Earth Sciences, Albany Museum, 40 Somerset Street, Makhanda, 6139, Eastern Cape, South Africa, and Department of Botany, Rhodes University, PO Box 94, Makhanda, 6140, Eastern Cape, South Africa.     

On the tracks of the earliest dinosaurs: implications for the hypothesis of dinosaurian monophyly

From the record of dinosaurian skeletal remains it has been inferred that the origin and initial diversification of dinosaurs were rapid events, occupying an interval of about 5 million years in the Late Triassic. By contrast numerous reports of dinosauroid tracks imply that the emergence of dinosaurs was a more protracted affair extending through much of the Early and Middle Triassic. This study finds no convincing evidence of dinosaur tracks before the late Ladinian. Each of the three dinosaurian clades — Theropoda, Sauropodomorpha, Ornithischia — produced a unique track morphotype that appears to be an independent modification of the chirotherioid pattern attributed to stem-group archosaurs (thecodontian reptiles). The existence of three divergent track morphotypes is consistent with the concept of dinosaurian polyphyly but can be reconciled with the hypothesis of dinosaurian monophyly only by invoking many and rapid reversals in the locomotor anatomy of early dinosaurs. The origin of dinosaurs was not the correlate or consequence of any single event or process, be it global change, competitive replacement, or opportunism in the wake of mass extinction. Instead the origin of dinosaurs is envisaged as a series of three cladogenetic events over an interval of at least 10 million years and possibly as much as 25 million years. This scenario of dinosaurian polyphyly is as well-supported by fossil evidence as is the currently favoured view of dinosaurian monophyly.     

New fossil damsel–dragonfly clarifies the phylogenetic position of the small Jurassic family Juraheterophlebiidae (Odonata: Epiproctophora)

HUANG D. & NEL A., June 2017. New fossil damsel -dragonfly clarifies the phylogenetic position of the small Jurassic family Juraheterophlebiidae (Odonata: Epiproctophora). Alcheringa, 41, 536–542.

A nearly complete specimen of Juraheterophlebia cancellosa sp. nov., the third species of the family Juraheterophlebiidae, is described from the Middle–Late Jurassic of China and shows the exact structure of its forewing discoidal space. As a consequence, this family is restored, separated from Erichschmidtiidae, and its diagnosis amended. It is transferred from Heterophlebioptera to Stenophlebioptera, the first clade being now only known from the Early Jurassic. Erichschmidtiidae includes the sole species Erichschmidtia nigrimontana, and this family is now considered of uncertain systematic position.

Diying Huang [dyhuang@nigpas.ac.cn] State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210,008, PR China; André Nel [anel@mnhn.fr] Institut de Systématique, Évolution, Biodiversité, ISYEB-UMR 7205-CNRS, MNHN, UPMC, EPHE, Muséum national d’Histoire naturelle, Sorbonne Universités, 57 rue Cuvier, CP 50, Entomologie F-75005, Paris, France.     

Making the Brain Plastic: Early Neuroanatomical Staining Techniques and the Pursuit of Structural Plasticity, 1910–1970

The concept of neuronal plasticity is widely used, but seldom defined in the neurosciences. It can signify many different occurrences, such as structural alterations of axons and dendrites (Cotman & Nadler, 1978), behavioural adaptations (Rosenzweig & Bennett, 1996), or physiological changes in synapse formation (Martin et al., 2000) at different stages of health and disease. Although there is such a wealth of research from many disciplines, the neuroanatomical aspects of plasticity are the focus of this paper. It seeks to illuminate the evolution of different concepts of plasticity concerning the structure and circuitry of the central nervous system (CNS). Early modern morphological research on de- and regeneration phenomena in the 19th- and early 20th-century is well documented. These studies, however, almost exclusively concentrated on the peripheral nervous system (PNS). It was one of the major contributions of Santiago Ramón y Cajal (1852–1934), that he applied the concept of regenerative capacities to the CNS. But the term plasticity seemed to have disappeared for about two decades after his death. The ensuing comeback of the expression may be attributed, at least in part, to new neuroanatomical staining and tracing methods. The pursuit of these techniques will serve as a guidepost through varying approaches in different times: It was the 1950s which seemed to spawn the time for new departures in structural investigations of neuronal plasticity.     

Kutjamarcoot brevirostrum gen. et sp. nov., a new short-snouted,early Miocene bandicoot (Marsupialia: Peramelemorphia) from the Kutjamarpu Local Fauna (Wipajiri Formation) in South Australia

Chamberlain, P.M., Travouillon, K.J., Archer, M. & Hand, S.J., November 2015. Kutjamarcoot brevirostrum gen. et sp. nov., a new short-snouted, early Miocene bandicoot (Marsupialia: Peramelemorphia) from the Kutjamarpu Local Fauna (Wipajiri Formation) in South Australia. Alcheringa 40, XX–XX. ISSN 0311-5518.

A new bandicoot species, Kutjamarcoot brevirostrum gen. et sp. nov. (Peramelemorphia), is described here from the Leaf Locality, Kutjamarpu Local Fauna (LF), Wipajiri Formation (South Australia). The age of the fossil deposit is interpreted as early Miocene on the basis of biocorrelation between multiple species in the Kutjamarpu LF and local faunas from the Riversleigh World Heritage Area (WHA). Kutjamarcoot brevirostrum is represented by isolated teeth and three partial dentaries and appears to have been short-snouted with an estimated mass of 920 g. Phylogenetic analyses place K. brevirostrum in a clade with extant Australian bandicoots and the extinct Madju, but potentially exclude the extant New Guinean bandicoots. Morphometric analysis infers close similarity between K. brevirostrum and species of Galadi in both size and rostral length. They, thus, potentially occupied compatible ecological niches with competitive exclusion perhaps explaining geographical segregation between these broadly coeval lineages.

Philippa M. Chamberlain [philippa.chamberlain@uq.net.au], School of Earth Sciences, University of Queensland, St Lucia, Queensland 4072, Australia; Kenny J. Travouillon [kenny.travouillon@museum.wa.gov.au; kennytravouillon@hotmail.com], Western Australian Museum, Locked Bag 49, Welshpool DC, WA, 6986, and School of Earth Sciences, University of Queensland, St Lucia, Queensland, 4072, Australia; Michael Archer [m.archer@unsw.edu.au] and Suzanne J. Hand [s.hand@unsw.edu.au], School of Biological, Earth and Environmental Sciences, University of New South Wales, New South Wales, 2052, Australia.     

Phylogenetic analysis of a new fossil Notonectidae (Heteroptera: Nepomorpha) from the Late Jurassic of China

Zhang W.T., Yao Y.Z. & Ren D., June 2012. Phylogenetic analysis of a new fossil Notonectidae (Heteroptera: Nepomorpha) from the Late Jurassic of China. Alcheringa, 239–250. ISSN 0311-5518.

A new fossil species Notonecta vetula sp. nov. is described and illustrated using nymph and adult fossil specimens collected from the Upper Jurassic Chijinqiao Formation, Yumen City, Gansu Province, China. A phylogenetic analysis, based on a combination of fossil and extant backswimmers, was conducted to confirm the position of the new fossil within the Notonectidae.

Wei-ting Zhang [zhangweitinghao@163.com], Yun-zhi Yao* [yaoyz100@gmail.com] and Dong Ren [rendong@mail.cnu.edu.cn], Key Lab of Insect Evolution and Environmental Changes, Capital Normal University, Beijing 100048, PR China; *Corresponding author; also affiliated with: State Key Laboratory of Palaeobiology and Stratigraphy (Nanjing Institute of Geology and Palaeontology, CAS), Nanjing 210008, PR China. Received 13.7.2011; revised 19.9.2011, accepted 27.9.2011.     

Two new stem-stoneflies discovered in the Pennsylvanian Avion locality,Pas-de-Calais,France (Insecta: ‘Exopterygota’)

Schubnel, T., Perdu, L., Roques, P., Garrouste, R. & Nel, A.,26 February 2019. Two new stem-stoneflies discovered in the Pennsylvanian Avion locality, Pas-de-Calais, France (Insecta: ‘Exopterygota’). Alcheringa 43, 430–435.

Avionptera communeaui gen. et sp. nov. and Gulou oudardi sp. nov., the second and third Carboniferous representatives of the stem group Plecoptera (after G. carpenteri) are described and illustrated. A. communeaui is attributed to the Paleozoic family Fatjanopteridae, of which the only previous member was Fatjanoptera mnemonica. Based on a re-examination of the families Gulouidae and Emphylopteridae, the former family is restored to the Plecoptera stem group and the latter is transferred to the Archaeorthoptera.

Thomas Schubnel [thomas.schubnel@wanadoo.fr], Romain Garrouste [garroust@mnhn.fr] and André Nel* [anel@mnhn.fr], Institut Systématique Evolution Biodiversité (ISYEB), Muséum National d’Histoire Naturelle, CNRS, Sorbonne Université, EPHE, 57 rue Cuvier, CP 50, 75005 Paris, France; Lubin Perdu [lubi.perdu@gmail.com], 11 rue du Caire, F-75002, Paris, France; Patrick Roques [patrick.roques93@wanadoo.fr], 2 Chemin des Processions, Neuilly-Plaisance, F-93049, France     

Pragian and lower Emsian (Lower Devonian) conodonts from Liujing,Guangxi, South China

LU, J.-F., QIE, W.-Q. & CHEN, X.-Q., July 2016. Pragian and lower Emsian (Lower Devonian) conodonts from Liujing, Guangxi, South China. Alcheringa 40, xxx–xxx. ISSN 0311-5518.

Lower Devonian (Pragian and Emsian) conodonts are described from the Liujing section in Guangxi, South China, highlighting the phylogeny of early polygnathids and establishing the basis for faunal correlations with deposits throughout the world. Records of Eognathodus kuangi sp. nov. and E. nagaolingensis Xiong increase the biodiversity of the Pragian eognathodids in South China and represent intermediate stages and probably the latest eognathodids in the evolutionary succession from Eognathodus to Polygnathus. During this evolutionary succession, the degeneration of the sulcus (or the flattening of the upper platform surface) is the most important morphological change, especially in the eognathodid lineage. Polygnathus trilinearis, P. pireneae and P. sokolovi are recognized together for the first time in South China. The contemporaneous occurrences of the kitabiformis and sokoloviformis morphs of P. pireneae with P. sokolovi and their respective similarities to P. kitabicus and P. sokolovi suggest that the latter two species are phylogenetically linked with P. pireneae. Evidence from the Liujing section also favours Polygnathus probably having evolved from Eognathodus in a tropical or subtropical area.

Jian-feng Lu* [lujfivan@sina.cn] and Xiu-qin Chen [xqchen@nigpas.ac.cn], Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, 39 East Beijing Road, Nanjing 210008, PR China; Wen-Kun Qie [wkqie@nigpas.ac.cn], Key Laboratory of Economic Stratigraphy and Palaeogeography, Nanjing Institute of Geology and Palaeontology, 39 East Beijing Road, Nanjing 210008, PR China. *Also affiliated with University of Chinese Academy of Sciences, Beijing 100049, PR China.     

Morphological analysis of Ozarkodina prolata Mawson and Ozarkodina midundenta (Wang & Ziegler) (Emsian conodonts) from South China

Lu, J.-F., November 2015. Morphological analysis of Ozarkodina prolata Mawson and Ozarkodina midundenta (Wang & Ziegler) (Emsian conodonts) from South China. Alcheringa 40, xxx–xxx. ISSN 0311-5518.

Investigations of conodonts from Emsian (Lower Devonian) strata at Bahe, Liujing and Daliantang in Guangxi and Yunnan, South China, provide new data on the morphological variability and phylogenetic affinity of Ozarkodina midundenta, a species initially assigned to Pandorinellina but transferred to Ozarkodina herein. Morphological analysis suggests that O. midundenta probably developed from O. prolata by progressive fusion of denticles in the middle third of the blade above the basal cavity in the Pa element.

Jian-feng Lu [lujfivan@sina.cn], Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, PR China. Also affiliated with University of Chinese Academy of Sciences, Beijing 100049, PR China.     

卢氏黑黄檀在红木中归属研讨

随着卢氏黑黄檀在我国大量使用,对卢氏黑黄檀的在红木中的归属纷争不断增加,为了讨论其在红木中的归属,试从木材解剖学、紫外光变色、紫外光照下官能团变化特征的傅立叶红外光分析和热变色四个不同角度对其进行研究鉴定。实验结果表明,卢氏黑黄檀的解剖学特征、紫外光变色的色度学变化趋势、热变色的色度学变化均与檀香紫檀一致,而与黄檀属黑酸枝类树种差别显著。本研究可为红木标准的逐步修正与完善提供参考。     

Cretaceous avian remains from Patagonia shed new light on the early radiation of birds

The anatomy of a new articulated enantiornithine bird skeleton from the Late Cretaceous of Patagonia clearly indicates a capacity for powered flight, approaching that of modern birds. Enantiornithines possess some of the synapomorphies of the Ornithurae, although they retain plesiomorphic states for many other characters, mainly in the hind limb. Such a mosaic character combination suggests a sister-group relationship between Enantiornithes and Ornithurae. Derived features of the pectoral girdle are here considered as diagnostic for a major avian clade, the Ornithopectae, comprising all known birds other than Archaeopteryx. The combination of derived and primitive traits in the fore and hind limbs and their girdles in early ornithopectines reflects mosaic evolution, with flight-related modifications of the fore limb and pectoral girdle preceding those in the hind limb and pelvic girdle.