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Диссертация / Dissertation САНКТ-ПЕТЕРБУРГСКИЙ ГОСУДАРСТВЕННЫЙ УНИВЕРСИТЕТ На правах рукописи Скучас Павел Петрович Ранние этапы эволюции саламандр (Lissamphibia, Caudata) и переход от стволовых к кроновым саламандрам Специальность 03.02.04 – ЗООЛОГИЯ ДИССЕРТАЦИЯ на соискание ученой степени доктора биологических наук Санкт-Петербург – 2018 2 Coдержание Введение……………………………………………………………………………………… 3 Глава 1. Морфологические признаки Caudata…………………........... 10 Глава 2. Саламандры стволовой группы………………………….………… 13 Глава 3. Стволовые саламандры и происхождение Caudata…………………………………………………………………………... 26 Глава 4. Происхождение современных (= кроновая группа; Urodela) саламандр………………………………….……………………. 31 Глава 5. Саламандры в мезозойских фаунах: эволюционный и палеобиогеографический аспекты………………………….………………………………………......... 37 5.1. Среднеюрская гомогенность фаун……………….......... 37 5.2. Юрское совместное распространение не- лиссамфибийных темноспондил и саламандр…………… 39 5.3. Раннемеловой сибирский рефугиум для юрских позвоночных………………………………………………………………….. 40 5.4. Позднемеловая азиатская летопись саламандр……………………………………………………………………… 43 Заключение…………………………………………………………………………………. 46 Благодарности…………………………………………………………………………….. 49 Список литературы……………………………………………………………………… 50 3 Введение Саламандры (Caudata) - одна из трёх ныне живущих клад лиссамфибий. Они характеризуются поверхностно примитивной внешней морфологией (т.е. хорошо развитым хвостом, а также передними и задними конечностями примерно одного размера) и преимущественно лавразийским распространением (например, Milner 2000). Первые саламандры появляются в ископаемой летописи в средней юре (бат) и представлены таксонами различных эволюционных уровней (а именно стволовыми и кроновыми саламандрами), некоторые из которых встречаются в одних и тех же местонахождениях (Evans et al. 1988; Nesov 1988; Evans and Waldman 1996; Milner 2000; Skutschas 2016a). Представители двух основных современных клад кроновой группы саламандр (Cryptobranchoidea (= Cryptobranchiformes в Milner 2000) и Salamandroidea (= Salamandriformes в Milner 2000)) появляются в ископаемой летописи в течении средней-поздней юры (Evans et al. 2005; Gao and Shubin 2003, 2012; Gao et al. 2013; Jia and Gao 2016). После своего первого появления, саламандры претерпели несколько основных эпизодов диверсификации, последние два из которых имели место в позднем мелу и во время палеоцен-эоценового термального максимума (Vieites et al. 2007). 4 Происхождение саламандр (как и происхождение лиссамфибий: саламандры, лягушки, червяги и вымершие альбанерпетонтиды) – один из самых противоречивых вопросов эволюции позвоночных. Большинство морфологических и палеонтологических исследований современных и ископаемых амфибий поддерживает гипотезу, что саламандры и лягушки являются сестринскими линиями и вместе эти таксоны образуют монофилетическую кладу Batrachia (например, Ruta and Coates 2007; Anderson et al. 2008; Marjanović and Laurin 2008; Sigurdsen and Green 2011; Skutschas and Martin 2011). Современные исследования также поддерживают происхождение Lissamphibia (или по крайней мере Batrachia) внутри темноспондильной клады Dissorophoidea (например, Ruta and Coates 2007; Anderson et al. 2008; Skutschas and Martin 2011; Maddin et al. 2012; для альтернативного мнения см. Marjanović and Laurin 2008, 2009). Наши знания о ранних этапах эволюции саламандр и появлении современных групп саламандр затруднены редкостью ископаемого материала, особенно для юрских базальных стволовых саламандр (Milner 2000). Современные открытия стволовых и кроновых саламандр в юрских и меловых отложениях (включая изученные мной находки из 5 Средней Азии, Казахстана и Сибири) начинают заполнять географические, временные, таксономические и анатомические пробелы в ископаемой летописи саламандр и, таким образом, улучшать наше понимание некоторых аспектов их ранней эволюции. Тем не менее, мы всё еще сравнительно мало знаем о мезозойских саламандрах и эта ситуация не улучшится до открытия новых местонахождений и образцов и без изучения и детального описания «ключевых саламандровых ископаемых и таксонов» (например, Karaurus и большинство других стволовых саламандр). Рисунок 1. Схема стратиграфической корреляции мезозойских свит Средней Азии, Казахстана и Сибири, содержащих остатки саламандр. Корреляции по работе Averianov and Sues (2012). 6 Основное внимание в моих исследованиях уделено саламандровым ископаемым и таксонам из мезозойских отложений Средней Азии, Казахстана и Сибири (Рис. 1, 2). Средняя Азия (регион охватывающий Киргизстан, Таджикистан, Туркменистан и Узбекистан), Казахстан и Сибирь вместе образуют огромную азиатскую территорию, которая содержит широко распространенные мезозойские наземные отложения (Несов 1997). Двенадцать геологических свит на этой территории содержат остатки саламандр (шесть в Средней Азии, две в Сибири и четыре в Казахстане). Мезозойские саламандры из этих регионов представляют особый интерес по следующим причинам: (1) юрские саламандры из Средней Азии, Сибири и Казахстана одни из геологически древнейших саламандр в ископаемой летописи; (2) летопись позднемеловых саламандр в Азии известна только из Средней Азии и Казахстана; (3) в Западной Сибири, среднеюрские и раннемеловые местонахождения содержащие остатки саламандр, позволяют проследить региональную эволюционную историю саламандр в течении примерно 40-милионного временного интервала; и (4) в Средней Азии и в Казахстане, хорошо задокументированная последовательность верхнемеловых наземных отложений (с сеномана по кампан) 7 содержащая остатки саламандр, позволяет проследить региональную эволюционную историю саламандр в течении примерно 20-милионного временного интервала. Рисунок 2. Карта, показывающая основные мезозойские местонахождения саламандр в Средней Азии, Казахстане и Сибири. На вставочной карте центральных и северных частей азиатского континента территория Средней Азии показана светло- серым, Казахстана – серым и Сибирь – тёмно-серым. 1 Ходжакуль (ходжакульская свита, сеноман), Средняя Азия, Узбекистан. 2 Итемир (джаракудукская свита, сеноман), Джаракудук (биссектинская свита, турон) и Айтым (айтымская свита, коньяк– сантон), все в Средней Азии, Узбекистан. 3 Тюлькели (жиркиндекская свита, турон), Казахстан. 4 Шах-Шах и Байбише (бостобинская свита, сантон–ранний кампан), все в Казахстане. 5 8 “Грей Меза” (= Алымтау 1) (дарбазинская свита, кампон), Казахстан. 6 Михайловка (карабастауская свита, киммеридж), Казахстан. 7 Кансай (яловачская свита, сантон), Средняя Азия, Таджикистан. 8 Кызылсу 1, Кугарт 1 и Ничке 1 (нижняя часть балабансайской свиты, бат), все в Средней Азии, Kyrgyzstan. 9 Шестаково (илекская свита, апт–альб), Сибирь, Россия. 10 Березовский карьер (итатская свита, бат), Сибирь, Россия. В дополнение к моему исследованию саламандр из мезозойских отложений Средней Азии, Казахстана и Сибири (Averianov et al. 2008; Skutschas 2009, 2013, 2014, 2016a, b; Skutschas and Krasnolutskii 2011; Skutschas and Martin 2011; Skutschas and Stein 2015; Skutschas and Boitsova 2017), я также провел исследования морфологии позвоночника и черепа саламандр (Skutschas and Baleeva 2012; Zhou et al. 2017), патологий у позднемеловых саламандр (Skutschas et al. in press), палеогеновых саламандр и родственных связей среди основных клад кроновых саламандр (Skutschas and Gubin 2012), и исследования по составу и эволюции амфибийного компонента наземных фаун позвоночных в Азии (Leshchinsky et al. 2003; Skutschas 2007; Skutschas et al. 2009, 2016; Averianov et al. 2015a, b, 2016a, b; Skutschas and Kolchanov 2017). Вместе данные исследования дали новые 9 представления о различных аспектах эволюционной истории саламандр. Основные методы, используемые в моих исследованиях, включают (1) классическое морфологическое описание, (2) микроКT (рентгеновская компьютерная микротомография), (3) гистологический анализ для документирования и интерпретации морфологии и гистологии, а также (4) кладистический анализ для выяснения филогенетических отношений изученных саламандровых таксонов. Основная цель моей исследовательской программы - осветить раннюю эволюционную историю саламандр (особенно по юрско-меловым стволовым и кроновым саламандрам из Средней Азии, Казахстана и Сибири). В дополнение новым представлениям о таксономии, палеобиогеографии и палеобиологии мезозойских саламандр, мои исследования также имеют значение для понимания происхождения саламандр и перехода от стволовой к кроновой группе саламандр. 10 Глава 1. Морфологические признаки Caudata Саламандры харктеризуются следующей уникальной комбинацией скелетных признаков: педицеллярные и двухвершинные зубы (непедицеллярные и одновершинные у некоторых неотенических саламандр, включая стволовые таксоны саламандр); укороченный передний отросток птеригоида, который спереди не контактирует с другими костями (удлиненный передний отросток птеригоида у некоторых неотенических саламандр); контакт теменной и чешуйчатой костей (отсутствует у некоторых продвинутых саламандр); отсутствие зубчиков на парасфеноиде; единое коракоидно-лопаточное окостенение (раздельные лопатка и коракоид у современных сиреновых саламандр); двуглавые поперечные отростки (плотно прижатые или одноголовчатые у некоторых саламандр); межкотилярный бугорок (= tuberculum interglenoideum) атласа (редуцирован у некоторых саламандр); опоры спинного мозга (= костные утолщения вдающиеся внутрь спинномозгового канала позвонков); бедренная кость, несущая гребень вертела и вертел (гребень вертела редуцирован у некоторых саламандр); basale commune (слившиеся дистальные 11 тарзалии 1 и 2) в стопе (например, Milner 2000; Gardner
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