The Mammals of the Late Eocene – Early Oligocene Solent Group

Part 1 begins a systematic account of the mammals from the British Solent Group. Their previous study is summarised. The stratigraphy is reviewed and lithostratigraphic logs are provided for the mammal-bearing localities. The new Fort Victoria Member replaces the previous restricted use Cliff End Member in the Headon Hill Formation. Seventeen species-group taxa of the placental euarchontan family Nyctitheriidae are described, with the new genera <i>Actinyctia</i> and <i>Cheilonyctia</i> and the new species <i>Amphidozotherium gassoni, Actinyctia bulbodens, Cheilonyctia lawsoni, Scraeva yulei, Euronyctia curranti</i> and <i>E. plesiolambda</i>. The occurrence of <i>Saturninia mamertensis</i> near the base of the Headon Hill Formation extends its range from the Bartonian to early Priabonian. The occurrence of <i>Oligonyctia hoffmani</i> in the Bembridge Limestone Formation and lower Hamstead Member extends its range from the early Rupelian to the late Priabonian. A phylogenetic analysis of European Bartonian–Rupelian Nyctitheriidae results in an expanded subfamily Amphidozotheriinae and a new subfamily Saturniniinae for <i>Saturninia</i> (<i>s.s</i>.), <i>Cryptotopos</i> and <i>Oligonyctia. Cryptotopos communis</i> and <i>Euronyctia recta</i> from the German Oligocene are transferred to the genus <i>Paradoxonycteris</i>, whilst <i>Sigenyctia</i> (type species <i>S. oligocaena</i>) is synonymised with the genus <i>Euronyctia. Saturninia mamertensis</i> and <i>S. grandis</i> are shown not to be members of this genus. <i>Euronyctia curranti</i>, <i>E. plesiolambda</i> and <i>E. oligocaena</i> form a stratigraphical morphocline, suggestive of an evolutionary sequence. A phylogenetic analysis of primitive eutherians confirms Nyctitheriidae as stem members of the superorder Euarchonta, supporting an earlier analysis. Aspects of evolution, faunal turnovers and diversity of locomotor adaptations during deposition of the Solent Group are discussed.

第一部分系统记述了英国索伦特群（Solent Group）的哺乳类化石，梳理了此前相关研究的进展。研究回顾了该类群的地层学背景，并为产出哺乳类化石的化石点提供了岩石地层柱状剖面。希顿希尔组（Headon Hill Formation）中此前应用范围受限的克里夫端段（Cliff End Member），将由新建立的维多利亚堡段（Fort Victoria Member）取代。本次研究记述了17个胎盘类真弓总目（Euarchonta）夜猿科（Nyctitheriidae）的种级分类单元，其中包含新属<Actinyctia>与<Cheilonyctia>，以及新种<Amphidozotherium gassoni>、<Actinyctia bulbodens>、<Cheilonyctia lawsoni>、<Scraeva yulei>、<Euronyctia curranti>和<E. plesiolambda>。在希顿希尔组底部附近产出的<Saturninia mamertensis>，其化石分布层位从巴尔顿阶（Bartonian）延伸至普里阿邦阶早期。在本布里奇灰岩组（Bembridge Limestone Formation）与汉斯特德段下部产出的<Oligonyctia hoffmani>，其分布层位从吕珀尔阶（Rupelian）早期扩展至普里阿邦阶晚期。针对欧洲巴尔顿阶-吕珀尔阶夜猿科的系统发育分析结果显示，Amphidozotheriinae亚科的分类范畴得到扩充，同时为<Saturninia>（狭义，s.s.）、<Cryptotopos>与<Oligonyctia>建立新亚科Saturniniinae。原发现于德国渐新统的<Cryptotopos communis>与<Euronyctia recta>被归入<Paradoxonycteris>属；而<Sigenyctia>（模式种为<S. oligocaena>）被并入<Euronyctia>属，成为其同物异名。<Saturninia mamertensis>与<S. grandis>被证实不属于该属。<Euronyctia curranti>、<E. plesiolambda>与<E. oligocaena>构成地层学形态渐变群，暗示存在演化序列。针对原始真兽类的系统发育分析证实，夜猿科属于真弓总目的基干类群，这一结果支持了此前的相关研究。本研究还探讨了索伦特群沉积时期的演化进程、动物群更替以及运动适应性多样性等相关议题。