EARLY RESEARCH OF PALEOZOIC AGNATHANS AND FISHES: THE STUDIES OF STEPAN SEMYONOVICH KUTORGA (1805-1861)

Agnathans and fishes with massive bone armors were widely spread among the vertebrates in the Early Paleozoic. Their remains were well preserved in fossil state. At present, many species of Devonian agnathans and fishes have been described and studied. Different taxonomic systems have been suggested based on their fossil exoskeletal elements. But in the first part of the nineteenth century, when scientists first came across such remains, their nature was not immediately understood. Discovered remains of armored ichthyofauna were identified as bones of reptiles and amphibians even by outstanding scientists of that time. Professor of the Imperial St. Petersburg University Stepan Semyonovich Kutorga was among them. This article supplies a brief biography of the scientist and an analysis of his works in the formative period of vertebrate paleontology in Russia. S. S. Kutorga was at the origin of the system of monographic descriptions and collections - the most important source of information in fundamental paleontological research. Kutorga’s collection, currently stored at the St. Petersburg State University, is the first monographic collection of Devonian ichthyofauna in our country.

Fossil mosses: What do they tell us about moss evolution?

The moss fossil records from the Paleozoic age to the Eocene epoch are reviewed and their putative relationships to extant moss groups discussed. The incomplete preservation and lack of key characters that could define the position of an ancient moss in modern classification remain the problem. Carboniferous records are still impossible to refer to any of the modern moss taxa. Numerous Permian protosphagnalean mosses possess traits that are absent in any extant group and they are therefore treated here as an extinct lineage, whose descendants, if any remain, cannot be recognized among contemporary taxa. Non-protosphagnalean Permian mosses were also fairly diverse, representing morphotypes comparable with Dicranidae and acrocarpous Bryidae, although unequivocal representatives of these subclasses are known only since Cretaceous and Jurassic. Even though Sphagnales is one of two oldest lineages separated from the main trunk of moss phylogenetic tree, it appears in fossil state regularly only since Late Cretaceous, ca. 70 million years ago (Ma), while earlier they were found twice as small leaf fragments from Lower Jurassic (ca. 200 Ma) and Late Ordovician (ca. 455 Ma). Pleurocarpous mosses appear in fossil state near the border between Jurassic and Cretaceous, although most Cretaceous mosses belong to acrocarps. Only in Eocene amber pleurocarps become more numerous than acrocarps. Some Eocene mosses can be assigned to extant families and sometimes genera, although the majority of Eocene pleurocarps are difficult to identify up to the family, as their morphology often allows placement of a particular specimen into several different families.

A new genus of fungus weevils (Coleoptera: Anthribidae) in Rovno amber

New fungus weevils, Eduardoxenus unicus (ZooBank registration: urn:lsid:zoobank.org:act:5732 BC85-9148-4FE5-A4F6-46847BA0138D, urn:lsid:zoobank.org: act:4D3B3EA8-AE0E-4E6D-A770-B427AC19ED03) Legalov, Nazarenko et Perkovsky, gen. et sp. nov. (Coleoptera: Anthribidae), are described from late Eocene Rovno amber. The new genus is similar to the genus Cyptoxenus Valentine, 1982, but differs in coarsely faceted eyes, antennomere 2 shorter than antennomere 1 and an almost glabrous body. It differs from the genus Valenfriesia Alonso-Zarazaga et Lyal, 1999 in the coarsely faceted eyes, almost straight transversal carina on the pronotum and distinct elytral humeri, and it differs from the genus Neoxenus Valentine, 1999 in distinct lateral carina on the pronotum, coarsely faceted eyes and almost straight transversal pronotal carina. This fossil fungus weevil is the oldest finding of the tribe Valenfriesiini in fossil state and the first record of the Choraginae from the Eocene amber. The palaeogeographical and palaeoclimatological importance of finding Valenfriesiini in Rovno amber is discussed.

VIII.—On the calcification of the vertebral centra in sharks and rays

In this paper are recorded the results of an investigation undertaken at the instance of Dr. A. Smith Woodward for the purpose of ascertaining to what extent the pattern presented by the calcified laminæ of the centrum is of value as an aid to the classification of Elasmobranch fishes, and to the identification of vertebræ found in the fossil state. The subject was dealt with exhaustively in 1879-1885 by Hasse, who, in his monograph ‘Das natürliche System der Elasmobranchier,’ claimed that the differences in the disposition of the calcified laminæ in the various genera and families of Elasmobranchs occur with such constancy and regularity that they may be accepted with confidence as an important factor in taxonomy. During the years, however, that have passed since the publication of this monograph the thesis has come to be looked upon with suspicion, and vertebrate morphologists at the present time do not, as a whole, regard Hasse’s definitions of the Cyclospondyli, Tectospondyli, and Asterospondyli as consistently applicable to the genera and species included by him within those groups. The material studied in the course of the investigation was to a large extent accumulated several years ago (see p. 313), and it was only the superior attraction of Cephalodiscus as a subject of research that prevented the work from being brought to an earlier conclusion. The examination of this accumulated material, and of that more recently acquired, was carried on in the Huxley Research Laboratory of the Imperial College of Science during the winter of 1917 and from May, 1919, to May, 1920, and I hereby acknowledge my great indebtedness to Prof. E. W. MacBride and the administrative officers of the College for the facilities offered there for the prosecution of the work. I have further to thank Prof. MacBride for frequent advice and for valuable suggestions made during the progress of the research. My thanks are also due, and are hereby tendered, to Dr. A. Smith Woodward and Mr. C. Tate Began, of the British Museum (Natural History), for many helpful hints and suggestions. Acknowledgments and thanks for material kindly furnished by various donors are recorded on p. 313.