Data from: Sauropod tooth morphotypes from the Upper Jurassic of the Lusitanian Basin (Portugal)
收藏资源简介:
The Upper Jurassic of the Lusitanian Basin has yielded an important fossil record of sauropods, but little information is available about the tooth morphotypes represented in this region. A large sample of teeth, both unpublished and published, is described and discussed here. Four main tooth morphologies are identified: spatulate, heart-shaped, pencil-shaped, and compressed cone-chisel-shaped. Heart-shaped teeth are considered to be exclusive to a non-neosauropod eusauropod, tentatively referred to Turiasauria. The spatulate teeth can be attributed to members of the Macronaria; they have a complex cingulum, more than one lingual facet and a labial ridge. The compressed cone-chisel-shaped teeth are also attributed to macronarians and the presence of an axially twisted apex through an arc of 30°–45° suggests putative affinities with Europasaurus and basal titanosauriforms. The variability observed in the overall morphology and wrinkling pattern of the compressed cone-chisel-shaped teeth may be due to factors related to the tooth position or to the ontogeny of individuals. Finally, pencil-shaped teeth with high slenderness index values, oval and apically located wear facets, subcylindrical crowns and lacking carinae, are tentatively assigned to Diplodocoidea. The diversity of tooth morphologies is in accordance with the known palaeobiodiversity of the Portuguese Late Jurassic sauropod fauna, which is composed of non-neosauropod eusauropods (turiasaurs), diplodocoids (diplodocids) and macronarians (camarasaurids and probably brachiosaurids). The Late Jurassic sauropod fossil record of the Iberian Peninsula presents the broadest tooth morphospace range in the world from this period, suggesting a wide niche partition for sauropods, and corresponding high taxonomic diversity.
卢西塔尼亚盆地(Lusitanian Basin)的上侏罗统地层产出了重要的蜥脚类(sauropods)化石记录,但该区域所发现的蜥脚类牙齿形态型相关资料却极为匮乏。本文对一批涵盖已发表与未发表的大型牙齿标本展开了描述与讨论。本次研究共识别出四种主要的牙齿形态:匙形、心形、铅笔形以及压缩锥凿形。心形牙齿被认为仅属于非新蜥脚类真蜥脚类(eusauropod),暂归入图里亚龙类(Turiasauria)。匙形牙齿可归属于大鼻龙类(Macronaria)成员,这类牙齿具有复杂的齿带(cingulum)、多个舌面凹以及一条唇脊(labial ridge)。压缩锥凿形牙齿同样属于大鼻龙类,其齿尖沿轴向扭转30°至45°的特征,暗示其与欧罗巴龙(Europasaurus)及基底泰坦龙形类(basal titanosauriforms)存在潜在亲缘关系。压缩锥凿形牙齿的整体形态与纹饰模式所呈现出的变异,可能与牙齿在颌骨中的位置或个体发育阶段相关。最后,具备高细长指数、卵圆形且位于齿尖处的磨蚀面、亚圆柱状齿冠且无齿脊(carinae)的铅笔形牙齿,暂被归入梁龙超科(Diplodocoidea)。本次识别的牙齿形态多样性,与葡萄牙晚侏罗世蜥脚类动物群已知的古生物多样性相契合:该动物群由非新蜥脚类真蜥脚类(图里亚龙类)、梁龙超科(梁龙科)以及大鼻龙类(圆顶龙科,可能还包括腕龙科)组成。伊比利亚半岛晚侏罗世的蜥脚类化石记录,拥有该时期全球最广泛的牙齿形态空间范围,这表明蜥脚类类群存在广泛的生态位分化,同时也对应着较高的分类多样性。



