New mixosaurid ichthyosaur specimen from the Middle Triassic of SW China: further evidence for the diapsid origin of ichthyosaurs

2011 ◽  
Vol 85 (1) ◽  
pp. 32-36 ◽  
Author(s):  
Jun Liu ◽  
Jonathan C. Aitchison ◽  
Yuan-Yuan Sun ◽  
Qi-Yue Zhang ◽  
Chang-Yong Zhou ◽  
...  

Recent cladistic analyses have all suggested a diapsid origin of ichthyosaurs. However, an intermediate evolutionary stage of the lower temporal region of ichthyosaurian skull between basal diapsids and derived ichthyosaurs has been absent from the fossil record. Here we describe the cranial skeleton of a new mixosaurid ichthyosaur specimen with a well-preserved lower temporal region from the Anisian Guanling Formation of eastern Yunnan. It is characterized by the most primitive lower temporal region within known ichthyosaurs. The primitive characters of the lower temporal region include both external and internal separation between the jugal and the quadratojugal, an anterior process of the quadratojugal, an apparent posteroventral process of the jugal, and a large lower temporal opening surrounded by the jugal, the postorbital, the squamosal, and the quadratojugal. The lower temporal region of this specimen provides the most direct evidence to the diapsid origin of ichthyosaurs. It also suggests that the disappearance of the lower temporal fenestra is caused initially by the reduction of the lower temporal arcade rather than the enlargement of the surrounding bones.

Zootaxa ◽  
2021 ◽  
Vol 5067 (1) ◽  
pp. 135-143
Author(s):  
ELENA D. LUKASHEVICH

The fossil record of Triassic Diptera is still poor, with the oldest dipteran assemblage described from the Upper Buntsandstein of the ‘Grès à Voltzia’ Formation (early Anisian, France). From the stratigraphically closest insect fauna of the Röt Formation of Lower Franconia, Germany, the first Diptera, Bashkonia franconica gen. et sp. nov. is described based on an isolated wing. The new genus is assigned to the family Nadipteridae, bridging the gap between two other genera included.  


10.4081/19 ◽  
2012 ◽  
Vol 153 (2) ◽  
pp. 257 ◽  
Author(s):  
Giovanni Pasini ◽  
Alessandro Garassino

Garassino<em> et al.</em> (2012) reported on a rich community of decapod crustaceans including axiideans, gebiideans, anomurans, and brachyurans from the Zanclean (Early Pliocene) of the “La Serra” quarry near San Miniato (Pisa, Tuscany, central Italy). In this decapod-rich assemblage some carapaces of the common pebble crab<em> Ristoria pliocaenica</em> (Ristori, 1891) (<em>Leucosiidae Samouelle</em>, 1819) are drilled in characteristic ways, due to the predatory activity of individuals belonging to two different taxa of marine clades, possibly naticids (Gastropoda, Naticoidea), and to octopodids (Cephalopoda, Octopoda). This is the first report of direct evidence of predation by cephalopods on crabs in the fossil record.


2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Shixue Hu ◽  
Qiyue Zhang ◽  
Rodney M. Feldmann ◽  
Michael J. Benton ◽  
Carrie E. Schweitzer ◽  
...  

2015 ◽  
Vol 11 (1) ◽  
pp. 20140911 ◽  
Author(s):  
Carly L. Manz ◽  
Stephen G. B. Chester ◽  
Jonathan I. Bloch ◽  
Mary T. Silcox ◽  
Eric J. Sargis

Small-bodied, insectivorous Nyctitheriidae are known in the Palaeogene fossil record almost exclusively from teeth and fragmentary jaws and have been referred to Eulipotyphla (shrews, moles and hedgehogs) based on dental similarities. By contrast, isolated postcrania attributed to the group suggest arboreality and a relationship to Euarchonta (primates, treeshrews and colugos). Cretaceous–Palaeocene adapisoriculid insectivores have also been proposed as early euarchontans based on postcranial similarities. We describe the first known dentally associated nyctitheriid auditory regions and postcrania, and use them to test the proposed relationship to Euarchonta with cladistic analyses of 415 dental, cranial and postcranial characteristics scored for 92 fossil and extant mammalian taxa. Although nyctitheriid postcrania share similarities with euarchontans likely related to arboreality, results of cladistic analyses suggest that nyctitheriids are closely related to Eulipotyphla. Adapisoriculidae is found to be outside of crown Placentalia. These results suggest that similarities in postcranial morphology among nyctitheriids, adapisoriculids and euarchontans represent separate instances of convergence or primitive retention of climbing capabilities.


2018 ◽  
Vol 5 (4) ◽  
pp. 23-27
Author(s):  
Ermilton Barreira Parente Júnior ◽  
Marlon Daniel Gomes Coelho ◽  
Thais Mahassem Cavalcante de Macedo Parente ◽  
Olivia Maria Veloso Coutinho ◽  
Oscar Nunes Alves

Introdução: Abscessos cerebrais múltiplos são focos de infecções piogênicas do parênquima cerebral que requerem uma atenção imediata e eficaz para reducão de morbimortalidade. A identificação do agente etiológico e do foco infeccioso normalmente é de grande valia na programação terapêutica. Esse trabalho busca relatar um raro caso de abscessos cerebrais múltiplos em paciente imunocompetente e sem fatores de risco evidentes, e o papel fundamental da antibioticoterapia empírica na resolução do caso. Relato do caso: Paciente, 75 anos, sem evidência de imunossupressão e doenças prévias iniciou quadro de alterações das atividades básicas da vida diária, confusão de tempo e espaço, hipersonia, lentificação da marcha, disartria e dor em pontada na região temporal direita que não cessava ao uso de analgésicos. Em Ressôncia magnética evidenciou-se múltiplos abscessos em região temporal gerando efeito de massa e hipertensão intracraniana. Realizado craniotomias com drenagens de secreções purulentas e culturas do material que não identificaram o agente etiológico. Discussão: A abordagem terapêutica dos abscessos cerebrais ainda não se encontra definida. Em virtude disso, cada caso tem sido conduzido de forma individualizada de acordo com a localização das lesões, seu estágio evolutivo e as condições clínicas do paciente. No caso em questão não indentificou-se a origem dos abscessos e a resolução do quadro foi obtida através das drenagens cirúrgicas em associação a antibioticoterapia empírica. Com os avanços da neuroimagem e da farmacologia, a redução da mortalidade por abscessos cerebrais reduziu para menos de 10%. Porém, a não identificação de um agente etiológico e diversas abordagens neurocirúrgicas podem acarretar em mais comorbidades para o paciente. Apresentamos um raro caso de abcessos cerebrais em paciente imunocompetente sem identificação de organismo agressor e o papel da antibioticoterapia empírica na resolução do caso.   Palavras-chave: abscesso encefálico; imunocompetência; diagnóstico;  terapêutica; antimicrobianos. ABSTRACT Introduction: Multiple brain abscesses are centers of pyogenic cerebral parenchymal infections that require immediate and effective attention to reduce morbidity and mortality. The identification of the etiologic agent and the infectious focus are usually of great value in terms of therapeutic planning. This paper seeks to report a rare case of multiple brain abscesses in an immunocompetent patient with no evident risk factors and the fundamental role that empirical antibiotic therapy plays in the resolution of the case. Case report: A 75-year-old patient with no evidence of immunosuppression and previous illnesses began to experience changes in her basic daily live activities, confusion in time and space, hypersomnia, gait slowing, dysarthria and stabbing pain in the right temporal region of the brain that would not cease even with use of analgesics. Magnetic Resonance revealed multiple abscesses in the temporal region generating mass effect and intracranial hypertension. It was performed craniotomies with drainage of purulent secretions and it was prepared cultures out of the material which resulted in no identification of the etiological agent. Discussion: The therapeutic approach of brain abscesses has not yet been defined. As a result, each case has been conducted in an individualized manner according to the location of the lesions, their evolutionary stage and the patient's clinical conditions. In the case of this report, the abscess’ origin was not identified and the resolution of the condition was obtained through surgical drainage in association with empirical antibiotic therapy. With advances in neuroimaging and pharmacology, reduction in mortality from brain abscesses reduced to less than 10%. However, failure to identify an etiologic agent and several neurosurgical approaches may lead to more comorbidities for the patient. We present a rare case of cerebral abscesses in an immunocompetent patient without identification of an aggressor organism and the importance of empirical antibiotic therapy in the resolution of the case. Keywords: brain abscess; immunocompetence; diagnosis; therapeutics; anti-infective agents.


2020 ◽  
Vol 94 (5) ◽  
pp. 966-978 ◽  
Author(s):  
Roy M. Farman ◽  
Phil R. Bell

AbstractThe Hawkesbury Sandstone (Hawkesbury Series, Sydney Basin) on the southeastern coast of New South Wales, Australia, preserves a depauperate but important vertebrate tetrapod body-fossil record from the Early and Middle Triassic. As with many fossil sites around the world, the ichnological record has helped to shed light on the paleoecology of this interval. Herein, we investigate historical reports of a trackway pertaining to a putative short-tailed reptile found at Berowra Creek in the 1940s. Reinvestigation of the surviving track-bearing slabs augmented by archival photographs of the complete trackway, suggests that these impressions, which consist primarily of didactyl tracks (plus less common monodactyl and tridactyl traces), represent the earliest example of a swimming tetrapod found in Australia. Another isolated specimen (possibly from a nearby locality at Annangrove) appears to represent similar didactyl swim traces of a second, larger individual. Although the identities of the trackmakers are unknown, the Berowra Creek individual had an estimated body length of between ~80 cm (short-coupled) and 1.35 m (long-coupled), and produced the subaqueous trackway while travelling upslope (against the current) on a sandbar within a braided river system of the Hawkesbury Sandstone. These trackways partially resemble amphibian swim traces in the so-called Batrachichnus C Lunichnium continuum, but appear to represent a unique locomotion trace. This reanalysis of the Berowra Creek trackway provides insight into the locomotion of tetrapods of the Triassic Hawkesbury Series, which remains a poorly understood aspect of their life history.


2018 ◽  
Vol 5 (3) ◽  
pp. 172337 ◽  
Author(s):  
Adriana López-Arbarello ◽  
Emilia Sferco

The phylogenetic relationships of the recently described genus † Ticinolepis from the Middle Triassic of the Monte San Giorgio are explored through cladistic analyses of the so far largest morphological dataset for fossil actinopterygians, including representatives of the crown-neopterygian clades Halecomorphi, Ginglymodi and Teleostei, and merging the characters from previously published systematic studies together with newly proposed characters. † Ticinolepis is retrieved as the most basal Ginglymodi and our results support the monophyly of Teleostei and Holostei, as well as Halecomorphi and Ginglymodi within the latter clade. The patterns of relationships within these clades mostly agree with those of previous studies, although a few important differences require future research. According to our results, ionoscopiforms are not monophyletic, caturids are not amiiforms and leptolepids and luisiellids form a monophyletic clade. Our phylogenetic hypothesis confirms the rapid radiation of the holostean clades Halecomorphi and Ginglymodi during the Early and Middle Triassic and the radiation of pholidophoriform teleosts during the Late Triassic. Crown-group Halecomorphi have an enormous ghost lineage throughout half of the Mesozoic, but ginglymodians and teleosts show a second radiation during the Early Jurassic. The crown-groups of Halecomorphi, Ginglymodi and Teleostei originated within parallel events of radiation during the Late Jurassic.


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