Paleopathology: Occurrence of Anomalies in the Elements of Devonian Conodonts
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aleopathology: Occurrence of Anomalies in the Elements of Devonian Conodonts V. M. Nazarovaa, * and L. I. Kononovaa aMoscow
State University, Moscow, Russia *e-mail: [email protected]
Received August 26, 2019; revised September 2, 2019; accepted September 2, 2019
Abstract—Twenty types of conodont element pathology are considered, and the examples of Abrasio, Accessio, Caudatio, Depressio, Diminutio, Duplicatio, Fusio, Impressio, Jugatio, Occlusio, and Suppressio pathologies identified in the Devonian of the Voronezh Anteclise are illustrated in detail. All pathological phenomena are assigned to five genetic groups: (1) mechanical damage to hard tissue; (2) disturbances of hard tissue growth due to soft tissue damage; (3) genetic changes; (4) changes caused by diseases; and (5) the results of normal functioning of the conodont elements. The frequency of occurrence is analyzed for the various pathology types. Keywords: conodonts, pathologies, Devonian DOI: 10.1134/S0031030120070102
INTRODUCTION The majority of conodont elements (especially the platform elements) possess distinct species-specific features. However, some features can be modified by various pathologies of element development, intravital damage and wear, or aging-related changes. The concept of conodont element pathology introduced by K. Weddige (Weddige, 1990) implies any deviation from a normal element shape. Twenty morphological types of conodont element pathology have been reported by now in works by different researchers (Weddige, 1990; Bikbaev and Snigireva, 2003; Tagarieva, 2013; Soboleva, 2014; Nazarova and Kononova, 2018); names derived from Latin roots were proposed for these pathologies (Table 1). The equivalents given in parentheses do not represent the precise translations from Latin in some cases, but characterize the essence of the phenomena. MATERIAL Large conodont collections from the boreholes and outcrops of the Voronezh Anteclise, their age ranging from the Mosolovian Regional Substage of the Eifelian Stage in the Middle Devonian to the Lebedyanian Regional Substage of the Famennian in the Late Devonian, were the material of this study. The profiles, data on their localization, and conodont lists were published earlier. The materials used in this study were retrieved from the Shchigry-16 (Nazarova and Kononova, 2016; Nazarova et al., 2019) and Shchigry-19 (Nazarova and Kononova, 2016) boreholes in the Kursk Region, the Naryshkino 4177 borehole (Naza-
rova, 1995; Nazarova and Kononova, 2016) in the Orel Region, Ul’yanovo UG-1 borehole (Nazarova, 1995; Kirilishina et al., 2009) in the Kaluga Region, Zadonskaya 1 borehole (Kirilishina et al., 2009; Kulashova et al., 2015) in the Lipetsk Region, Prosvet 2P borehole (Nazarova and Kononova, 2016) in the Bryansk Region, and Novokhoperskaya 8750/1 borehole (Kirilishina et al., 2009; Nazarova and Kononova, 2016), Semiluki outcrop (Ovnatanova and Kononova, 2001), and Gornostaevka quarry (Kirilishina et al., 2009) in the Voronezh Region. A CamScan scanning electron microscope (PIN RAS) and a Le
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