35 research outputs found

    On a remarkable new species of <i>Tharsis</i>, a Late Jurassic teleostean fish from southern Germany: its morphology and phylogenetic relationships

    Get PDF
    A complete morphological description, as preservation permits, is provided for a new Late Jurassic fish species (Tharsis elleri) together with a revision and comparison of some morphological features of Tharsis dubius, one of the most common species from the Solnhofen limestone, southern Germany. An emended diagnosis of the genus Tharsis – now including two species – is presented. The new species is characterized by a combination of morphological characters, such as the presence of a complete sclerotic ring formed by two bones placed anterior and posterior to the eye, a moderately short lower jaw with quadrate-mandibular articulation below the anterior half of the orbit, caudal vertebrae with neural and haemal arches fused to their respective vertebral centrum, and parapophyses fused to their respective centrum. A phylogenetic analysis based on 198 characters and 43 taxa is performed. Following the phylogenetic hypothesis, the sister-group relationship Ascalaboidae plus more advanced teleosts stands above the node of Leptolepis coryphaenoides. Both nodes have strong support among teleosts. The results confirm the inclusion of Ascalabos, Ebertichthys and Tharsis as members of this extinct family. Tharsis elleri n. sp. (LSID urn:lsid:zoobank.org:act:6434E6F5-2DDD-48CF-A2B1-827495FE46E6, date: 13 December 2018) is so far restricted to one Upper Jurassic German locality – Wegscheid Quarry near Schernfeld, EichstĂ€tt – whereas Tharsis dubius is known not only from Wegscheid Quarry, but also from different localities in the Upper Jurassic of Bavaria, Germany, and Cerin in France.</p

    The first record of Late Jurassic crossognathiform fishes from Europe and their phylogenetic importance for teleostean phylogeny

    No full text
    The Late Jurassic Bavarichthys incognitus, n. gen. n. sp. from Ettling, Bavaria, is described. The new species represents the oldest record of a crossognathiform in Europe and together with Chongichthys from the Oxfordian of South America stands at the basal levels of a clade including crossognathids and pachyrhizodontoids. In addition, the new fish represents the first record of a crossognathiform in the Solnhofen Limestones. The new genus is characterized by numerous features such as the presence of infraorbitals 1–3 independent and 4 + 5 fused; two supramaxillary bones present; supramaxilla 2 considerably shorter than supramaxilla 1 and lacking an antero-dorsal process; well-developed series of epineural, epicentral and epipleural intermuscular bones; parhypural and hypurals 1 and 2 partially fused to each other; a series of epaxial basal fulcra; and a few, elongate fringing fulcra associated with the dorsal leading margin of caudal fin. doi:10.1002/mmng.201000005</a

    A novel cryptic splice site mutation in <em>COL1A2</em> as a cause of osteogenesis imperfecta.

    No full text
    Osteogenesis imperfecta (OI) is an inherited genetic disorder characterized by frequent bone fractures and reduced bone mass. Most cases of OI are caused by dominantly inherited heterozygous mutations in one of the two genes encoding type I collagen, COL1A1 and COL1A2. Here we describe a five-year-old boy with typical clinical, radiological and bone ultrastructural features of OI type I. Establishing the molecular genetic cause of his condition proved difficult since clinical exome and whole exome analysis was repeatedly reported negative. Finally, manual analysis of exome data revealed a silent COL1A2 variant c.3597 T &gt; A (NM_000089.4), which we demonstrate activates a cryptic splice site. The newly generated splice acceptor in exon 50 is much more accessible than the wild-type splice-site between the junction of exon 49 and 50, and results in an in-frame deletion of 24 amino acids of the C-terminal propeptide. In vitro collagen expression studies confirmed cellular accumulation and decreased COL1A2 secretion to 45%. This is the first report of a cryptic splice site within the coding region of COL1A2. which results in abnormal splicing causing OI. The experience from this case demonstrates that routine diagnostic approaches may miss cryptic splicing mutations in causative genes due to the lack of universally applicable algorithms for splice-site prediction. In exome-negative cases, in-depth analysis of common causative genes should be conducted and trio-exome analysis is recommended
    corecore