Mesozoic and Palaeocene lissamphibian assemblages of North America: a comprehensive review
Mesozoic and Palaeocene lissamphibian assemblages of North America: a comprehensive review
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北美中生代和古新世双栖动物组合：全面回顾
DOI：
10.1007/s12549-013-0130-z
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发表时间：
2013
影响因子：
1.4
通讯作者：
D. Demar
中科院分区：
文献类型：
--
作者：
J. Gardner;D. Demar
本文根据61个地质建造中400多个已发表和未发表的化石记录，对北美中生代和古新世的利桑菲宾类化石（即无尾类、尾类、裸鳞类和白斑类）进行了评述。尽管已知一些相关的和铰接的骨骼以及罕见的足迹和轨道，但该记录严重偏向于孤立的骨骼。大部分地区位于西部内陆：加拿大阿尔伯塔中部和南部以及萨斯喀彻温省南部，向南延伸穿过美国并进入北方墨西哥。在该地区之外，记录仅限于下加利福尼亚的一个晚白垩世地层和美国东部的几个晚三叠世和白垩纪地层。晚三叠世（卡尼期中期和诺利期早期）就有可能发现丽桑菲比亚人。Unambiennialissampibian是已知的从早侏罗世（Sinemurian-Pliensbachian），晚侏罗世（Kimmeridgian-最早的Tithonian），基白垩纪（晚Berriasian-Valanginian）和一个几乎连续的序列从Aptian延伸到古新世末期。亚利桑那州的早侏罗世（Sinemurian-Pliensbachian）记录了全球最古老的无尾类（即冠蛙）和茎盲猴化石;后者也是第四纪之前唯一的北美裸腹蛙化石。在科罗拉多、犹他州和怀俄明州的晚侏罗世（基默里季期-最早的提东期）沉积物中含有中等多样性的无尾类、有尾类（即冠蝾螈）和可能的茎蝾螈。在南达科他州的一个白垩纪基底地区（晚贝里阿斯-瓦兰吉尼期）发现有尾目动物，也是北美第一个发现有尾目动物的地区。在蒙大拿州、怀俄明州、德克萨斯州和俄克拉荷马州的阿普第期/阿尔必安期地点，含有无尾两栖类、有尾两栖类和阿尔班纳佩托恩两栖类的混合体，这种三重的利桑菲宾类组合在北美一直持续到白垩纪的剩余时间，并间歇性地持续到古新世。大多数无尾两栖动物的亲缘关系不确定。有尾目包含了灭绝的科（Scapherpetontidae和Batrachosauroididae）的混合体，这些科在白垩纪到古近纪早期都很突出，沿着最早出现的几个现存科，特别是Santonian的海牛科，Maastrichtian晚期的Amphiumids和Proteids，以及古新世晚期的双齿类和明确的隐鳃类。Albanerpetontid属Albanerpeton在白垩纪和古新世期间具有适度的多样性，直到古新世末期从北美记录中消失。北美lissampibians的时间丰富度估计计算的基础上taxic和最低谱系水平发生数据每5百万年的时间间隔开始在早侏罗世，虽然到古新世结束。由此产生的丰富度曲线表现出的一般模式，丰富度的增加导致的古近纪（K-Pg）的边界，在坎帕尼亚和马斯特里赫特的峰值和下降之后。该模式的后半部分表明，与以前的估计相比，K-Pg边界上的lissampibians的灭绝率更高，我们将其归因于我们较粗的时间分级，分类学添加和一些早期分类学鉴定的变化。虽然整体丰富的模式可能至少部分反映了一个真实的信号，它是严重影响因素，如埋藏学，时间间隔，化石采样和出版偏向于特定的间隔和分类组，更详细的研究，所有主要lissampibian分支需要证实这些发现。这篇评论强调了北美lissampibian记录的中生代和古新世部分的优点和缺点，并为未来的工作提供了一个框架。
The Mesozoic and Palaeocene record of lissamphibians (i.e. anurans, caudates, gymnophionans and albanerpetontids) in North America is reviewed on the basis of over 400 published and unpublished occurrences from 61 geological formations. The record is heavily biased towards isolated bones, although some associated and articulated skeletons and rare tracks and trackways are known. Most of the localities are in the Western Interior: in central and southern Alberta and southern Saskatchewan, Canada, extending southwards through the USA and into northern Mexico. Outside of that region, records are limited to one Late Cretaceous age formation in Baja California and several Late Triassic and Cretaceous age formations in the eastern USA. Putative lissamphibians have been reported from the Late Triassic (middle Carnian and early Norian). Unambiguous lissamphibians are known from the Early Jurassic (Sinemurian–Pliensbachian), the Late Jurassic (Kimmeridgian–earliest Tithonian), the basal Cretaceous (late Berriasian–Valanginian) and a nearly continuous sequence extending from the Aptian through to the terminal Palaeocene. The Early Jurassic (Sinemurian–Pliensbachian) of Arizona documents the oldest global occurrences of an anuran (i.e. crown frog) and a stem caecilian; the latter also is the only North American fossil occurrence for Gymnophiona prior to the Quaternary. Late Jurassic (Kimmeridgian–earliest Tithonian) age deposits in Colorado, Utah and Wyoming contain a moderate diversity of anurans, urodeles (i.e. crown salamanders) and possibly stem salamanders. A basal Cretaceous locality (late Berriasian–Valanginian) in South Dakota contains a urodele and the first North American occurrence for Albanerpetontidae. Aptian/Albian age localities in Montana, Wyoming, Texas and Oklahoma contain a mixture of anurans, urodeles and albanerpetontids—that tripartite lissamphibian composition persists in North America through the remainder of the Cretaceous and intermittently through the Palaeocene. Most of the anurans are of uncertain familial affinities. The urodeles contain a mixture of extinct families (Scapherpetontidae and Batrachosauroididae) that were prominent through the Cretaceous into the early Palaeogene, along with the earliest appearances of several extant families, specifically sirenids in the Santonian, amphiumids and proteids in the late Maastrichtian and dicamptodontids and unequivocal cryptobranchids in the late Palaeocene. The albanerpetontid genus Albanerpeton was moderately diverse during the Cretaceous and Palaeocene, before vanishing from the North American record near the end of the Palaeocene. Temporal richness estimates of North American lissamphibians were calculated based on taxic and minimum lineage level occurrence data per 5 million year time interval beginning in the Early Jurassic and though to the end of the Palaeocene. The resulting richness curves demonstrate a general pattern of increasing richness leading up to the Cretaceous-Palaeogene (K-Pg) boundary, with peak values during the Campanian and Maastrichtian and a decline thereafter. The latter part of that pattern suggests higher extinction rates for lissamphibians across the K-Pg boundary compared to previous estimates, which we attribute to our coarser temporal binning, taxonomic additions and changes to some earlier taxonomic identifications. Although the overall richness pattern may at least partially reflect a true signal, it is heavily influenced by factors such as taphonomy, temporal gaps, fossil sampling and publication biases towards particular intervals and taxonomic groups; more detailed studies of all major lissamphibian clades are needed to corroborate these findings. This review highlights the strengths and weaknesses of the Mesozoic and Palaeocene portion of the North American lissamphibian record and provides a framework for future work.