当前位置: X-MOL 学术J. Syst. Palaeontol. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
The first three-dimensional fossils of Cretaceous sclerorhynchid sawfish: Asflapristis cristadentis gen. et sp. nov., and implications for the phylogenetic relations of the Sclerorhynchoidei (Chondrichthyes)
Journal of Systematic Palaeontology ( IF 2.2 ) Pub Date : 2019-04-11 , DOI: 10.1080/14772019.2019.1578832
Eduardo Villalobos-Segura 1 , Charlie J. Underwood 1, 2 , David J. Ward 2 , Kerin M. Claeson 3
Affiliation  

A new fossil batoid (ray), Asflapristis cristadentis gen. et sp. nov., is described from six exceptionally well-preserved, three-dimensional skeletal remains from the Turonian (Late Cretaceous) of Morocco. Mechanical and acid preparation and computed tomographic scanning of these specimens reveal details of much of the proximal skeleton, especially the skull, synarcual and pectoral skeleton, with only the more distal parts of the skeleton missing. These fossils represent a relatively large animal (62 cm preserved length, estimated total length approximately 2 metres) possessing a robust rostrum that lacks enlarged rostral denticles. It has a narrow and small chondrocranium with jaws that are relatively large compared to the rest of the skull and robust with highly ornamented teeth that lack cusps. The branchial skeleton shows a large second hypobranchial without an anterior process, which was probably fused to the basibranchial as in other sclerorhynchoids. The synarcual is large and lacks centra through its entire length, with no direct connection to the pectoral girdle observed. Pectoral fins probably possessed enlarged proximal elements (propterygium, mesopterygium and metapterygium); the articulation facet between the coracoid and the pectoral elements was reduced. A phylogenetic analysis using both parsimony and Bayesian methods was performed incorporating this new taxon. Both analyses recovered a phylogenetic topology that places the sclerorhynchoids in a close relation to rajoids and clearly separated from the morphologically similar Pristidae within the Rhinopristiformes. With respect to the extant taxa, the phylogenies generated are similar to that obtained from molecular analysis of modern batoids. The palaeoecological implication of this discovery suggests that the Asfla assemblage was not from a ‘normal’ open carbonate shelf but rather a restricted environment favouring a low-diversity chondrichthyan fauna.

http://zoobank.org/urn:lsid:zoobank.org:pub:7752385F-817D-40BF-961C-1AF7B9093E14



中文翻译:

白垩纪巩膜棘鱼的第一个三维化石:Asflapristis cristadentis gen。等。十一月,及其对Scholorhynchoidei(Chondrichthyes)的系统发育关系的启示

一种新的化石batoid(射线),Asflapristis cristadentisgen。等。nov。,是从摩洛哥Turonian(晚白垩世)的六个保存完好的三维骨骼遗骸中描述的。机械和酸制备以及这些标本的计算机断层扫描显示了许多近端骨骼的细节,尤其是颅骨,舌骨和胸骨的骨骼,只有骨骼的更远端部分缺失。这些化石代表了一个相对较大的动物(保留长度为62厘米,估计总长度约为2米),具有坚固的讲台,没有大型的鼻尖齿。它有一个狭窄而小型的软骨颅骨,其下颌比头骨的其余部分要大,而健壮的牙齿却没有尖锐的装饰性。branch骨骨架显示第二大的支气管下支,没有前突,可能像其他巩膜软骨样肌一样融合到了支气管。趾骨大,在整个长度上都没有中心,与观察到的腰带没有直接的联系。胸鳍可能具有扩大的近端元素(翼状me肉,中翼状and肉和翼状ery肉);减少了喙突和胸腔之间的关节运动。结合此新分类单元,使用简约和贝叶斯方法进行了系统发育分析。两种分析都恢复了系统发育的拓扑结构,使巩膜突突突突科与近端突突突科密切相关,并与鼻形目内的形态相似的Pristidae明显分开。关于现存的分类群,所产生的系统发育类似于从现代类蝙蝠的分子分析获得的系统发育。

http://zoobank.org/urn:lsid:zoobank.org:pub:7752385F-817D-40BF-961C-1AF7B9093E14

更新日期:2019-04-11
down
wechat
bug