Putative dicynodont coprolites from the Upper Triassic of Poland
Putative dicynodont coprolites from the Upper Triassic of Poland
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DOI：
10.1016/j.palaeo.2014.06.013
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发表时间：
2014-10-01
影响因子：
3
通讯作者：
Niedzwiedzki, Grzegorz
中科院分区：
文献类型：
--
作者：
Bajdek, Piotr;Owocki, Krzysztof;Niedzwiedzki, Grzegorz
在波兰卢布利涅克镇附近利索维兹的Lipie Slskie粘土坑的上三叠统(最上层的诺里安-下拉伊特)沉积中，收集到了大量(超过100个)棕色到黑色和粉红色的碳酸盐或黄铁矿矿化的、部分富有机碳的球形或椭圆形结构。它们的地质背景、形态、含量、地球化学以及与骨骼遗骸的联系表明，它们是一种相当大的食草性四足动物的粪便块。该遗址唯一已知的大型食草动物是一只巨大的5米长的双齿目恐龙(突触目：双齿目)，由大量的骨骼和巨大的椭圆形脚印代表。从泥岩和粉砂岩中采集到推定的双圆齿珊瑚化石，并在缺氧条件下沉积了大量的有机遗迹。此外，稀土元素和其他微量元素的含量表明，这些粪长岩的埋藏环境和成岩作用处于缺氧条件下。扫描电子显微镜和薄片图像显示了大量含有黄铁矿(可能是细菌起源)的巢穴和大量的矿物颗粒。推测的双齿藻壳还含有无定形的深色有机质，保存不佳的孢囊状结构，植物角质层的小碎片。这些粪便化石的详细特征揭示了可能对原始动物物种的生态学和生理学的影响。测得裸子植物角质层和暗色有机质的C-13值平均值分别为-23.4‰、-21.2‰和-20.3‰。这些粪便化石的证据表明，二齿龙将植物软质元素加工成非常小的碎片，但在两个粪便化石中也发现了大量积累的木屑。(C)2014爱思唯尔B.V.保留所有权利。
A significant number (more than 100) of brown to dark and silty, carbonate or pyrite-mineralized, in part organic carbon-rich, spherical or oval-shaped structures have been collected from the Upper Triassic (uppermost Norian-lower Rhaetian) sediments of the Lipie Slskie clay-pit at Lisowice near Lubliniec town, Poland. Their geological context, morphology, content, geochemistry and association with skeletal remains suggest they are fecal masses of a sizable herbivorous tetrapod. The only large herbivore known from the site is a giant 5 meter-long dicynodont (Synapsida: Anomodontia), represented by numerous bones and also by large, oval-shaped footprints. The putative dicynodont coprolites were collected from mudstone and siltstone with numerous organic remains that were deposited in anoxic conditions. In addition, REEs and other trace element concentrations suggest that the burial environment and diagenesis of these coprolites were under anoxic conditions. SEM and thin section images of the coprolite matrix show numerous nests with pyrite (probably bacterial in origin) and large amount of mineral particles. The putative dicynodont coprolites contain also amorphous, dark organic matter, poorly preserved palynomorphs, small fragments of plant cuticle. Detailed characteristic of these coprolites reveals possible implications for the ecology and physiology of the source animal species. The delta C-13 values of the gymnosperm cuticle and dark organic matter measured in three coprolites are -23.4 parts per thousand, -21.2 parts per thousand and -20.3 parts per thousand, all average. The evidence from these coprolites suggests that dicynodonts processed plant soft elements into very small pieces, but wood fragments were found also in a mass accumulation in two coprolites. (c) 2014 Elsevier B.V. All rights reserved.