Paleobiology of the Late Cretaceous sclerorhynchid sawfish, Ischyrhiza mira (Elasmobranchii: Rajiformes), from North America based on new anatomical data
Paleobiology of the Late Cretaceous sclerorhynchid sawfish, Ischyrhiza mira (Elasmobranchii: Rajiformes), from North America based on new anatomical data
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基于新解剖数据的北美洲白垩纪晚期硬吻锯鳐 Ischyrhiza mira（Elasmobranchii：Rajiformes）的古生物学
DOI：
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
K. Shimada
中科院分区：
文献类型：
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作者：
Phil Sternes;K. Shimada
摘要：我们描述了来自美国田纳西州和阿拉巴马州坎帕尼亚-下马斯垂克地区的晚白垩世硬颈锯鳐Ischyrhiza mira的7具相关骨骼遗骸，以解读其古生物学。坐骨根有大约16或17个功能刺在茎台两侧有大约相同数量的替代刺其中高大直立的刺占据了茎台前部的1 / 2到2 / 3后面是较小的刺。喙部分布着小的帽状真皮小齿，而身体背面分布着大的刺状真皮小齿，这是一种懒散的底栖类动物的特征。我们同意先前被鉴定为Peyeria的吻侧棘的标本实际上是硬齿猴的扩大的刺状真皮小齿的解释。我们认为，硬喙儿的喙长与体长之比一般约为1:3.27。我们基于脊椎骨的mira个体发生分析给出了一个190厘米长的个体的年龄估计为12.4岁，出生时的大小约为0.5米，该物种的最大可能长度不超过3米。与现存的棱镜形锯鳐相比，米拉锯鳐性成熟的时间可能要早得多，喙部发育的速度也略快。
Abstract We describe seven associated skeletal remains of Ischyrhiza mira, a Late Cretaceous sclerorhynchid sawfish, from the Campanian‒lower Maastrichtian of Tennessee and Alabama, U.S.A., to decipher its paleobiology. Ischyrhiza mira had about 16 or 17 functional spines and about the same number of replacement spines on each side of the rostrum in which tall erect spines occupied the anterior one-half to two-third of the rostrum followed posteriorly by smaller spines. Whereas small hat-shaped dermal denticles were distributed on the rostrum, large thorn-like dermal denticles were present on the dorsal side of the body characteristic of sluggish, benthic batoids. We concur with the interpretation that specimens previously identified as rostral spines of Peyeria are actually enlarged thorn-like dermal denticles of a sclerorhynchid. We suggest that the ratio between the rostrum length and total body length of sclerorhynchids was generally about 1:3.27. Our vertebra-based ontogenetic analysis of I. mira gives an age estimate of 12.4 years for a 190-cm-long individual, the size at birth of about 0.5 m, and the maximum possible length for the species of no more than 3 m. Compared to extant pristid sawfishes, I. mira probably became sexually mature much earlier with a slightly faster rate of rostrum development.
硬喙鱼与喙软骨鱼类的趋同进化
DOI：
10.1144/sp430.7
发表时间：
2015
期刊：
Geological Society, London, Special Publications
影响因子：
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作者：
Underwood C
通讯作者：
Underwood C