Blanco Alejandro, Puértolas-Pascual Eduardo, Marmi Josep, Vila Bernat, Sellés Albert G
Institut Català de Paleontologia Miquel Crusafont, Universitat Autònoma de Barcelona, C/Escola Industrial 23, E-08201, Sabadell, Spain.
Grupo Aragosaurus-IUCA, Área de Paleontología, Facultad de Ciencias, Universidad de Zaragoza, Pedro Cerbuna 12, 50009, Zaragoza, Spain.
PLoS One. 2014 Dec 31;9(12):e115837. doi: 10.1371/journal.pone.0115837. eCollection 2014.
The controversial European genus Allodaposuchus is currently composed of two species (A. precedens, A. subjuniperus) and it has been traditionally considered a basal eusuchian clade of crocodylomorphs. In the present work, the new species A. palustris is erected on the base of cranial and postcranial remains from the lower Maastrichtian of the southern Pyrenees. Phylogenetic analyses here including both cranial and postcranial data support the hypothesis that Allodaposuchus is included within Crocodylia. The studied specimen suggests little change in postcranial skeleton along the evolutionary history of crocodylians, except for some bone elements such as the axis, the first caudal vertebra and the ilium. The specimen was found in an organic mudstone corresponding to a coastal wetland environment. Thus, A. palustris from Fumanya is the first Allodaposuchus reported in lacustrine-palustrine settings that expand the ecological range for this genus. The S-DIVA palaeobiogeographic reconstruction of ancestral area suggests that early members of Crocodylia rapidly widespread for the Northern Hemisphere landmasses no later than the Campanian, leading the apparition of endemic groups. In that way "Allodaposuchia" represents an endemic European clade probably originated in the Ibero-Armorican domain in the late Campanian and dispersed by the Southern European archipelago prior to the early Maastrichtian.
有争议的欧洲鳄属Allodaposuchus目前由两个物种组成(A. precedens、A. subjuniperus),传统上它被认为是鳄形类的一个基干真鳄类分支。在本研究中,新物种A. palustris是根据来自比利牛斯山脉南部下马斯特里赫特阶的颅骨和颅后骨骼化石建立的。这里包括颅骨和颅后数据的系统发育分析支持了Allodaposuchus属于鳄目的假说。研究标本表明,除了一些骨骼元素如枢椎、第一尾椎和髂骨外,鳄类动物进化史上颅后骨骼变化不大。该标本发现于一块与沿海湿地环境对应的有机泥岩中。因此,来自富马尼亚的A. palustris是首个在湖沼-沼泽环境中报道的Allodaposuchus,这扩大了该属的生态范围。祖先区域的S-DIVA古生物地理重建表明,鳄目早期成员在不晚于坎帕阶时迅速扩散到北半球大陆,导致了特有类群的出现。这样一来,“Allodaposuchia”代表了一个可能起源于晚坎帕阶伊比利亚-阿莫里卡地区、在早马斯特里赫特阶之前通过南欧群岛扩散的欧洲特有分支。