Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, 100044, China.
CAS Center for Excellence in Life and Paleoenvironment, Beijing, 100044, China.
Sci Rep. 2021 Apr 12;11(1):7891. doi: 10.1038/s41598-021-87090-5.
In this paper, seven coprolites from the Lower Cretaceous of Tsagan-Tsab formation have been described. Thus, producing a significant contribution to what we perceived as the first detailed study of coprolites from the Mesozoic deposits in Mongolia. The collected coprolites encompass a total of six spiral amphipolar and one scroll coprolites. We prominently identified four new coprolite ichnotaxa, such as: Hyronocoprus tsagantsabensis and Hyronocoprus hunti, to which both are ichnosp. nov.; followed by Megakalocoprus barremianensis and Scrollocoprus tatalensis, where both are ichnogen. et ichnosp. nov. Notably, CT scans revealed that all specimens showed various amounts of bony inclusions and scales, hence, deducing that the producers could have had a low acidic digestive track and were unable to dissolve bone matters. Moreover, SEM-EDS analysis concluded its carnivorous nature, thus, pointing towards piscivorous diet. The small sized Scrollocoprus is considered to be the second findings of Mesozoic era's scroll coprolites, which contain possible plant pollens, a complete infraorbital bone, clusters of bone fragments and rhomboidal-shaped ganoid scales of the prey; and bioerosional scars have been observed on the surface. We suggest those amphipolar spiral ichnotaxa were produced by Asipenceriformes, with Pholidophoriformes as the prey, while Scrollocoprus represents fecal excrement of underived fish, possibly of sarcopterygian origins.
本文描述了产自下白垩统 Tsagan-Tsab 组的七枚粪化石。这为我们对蒙古中生代地层中首次详细研究粪化石做出了重要贡献。所采集的粪化石共有六枚旋卷两歧形粪化石和一枚旋曲形粪化石。我们明确鉴定出四个新的粪化石遗迹种，例如：Tsagantsabensis 旋卷两歧形粪化石和 Hunti 旋卷两歧形粪化石，两者均为遗迹种新种；此外还有 Barremianensis 巨两歧形粪化石和 Tatalensis 旋曲形粪化石，两者均为遗迹属和遗迹种新种。值得注意的是，CT 扫描显示所有标本均含有不同数量的骨内含物和鳞片，因此推断其生产者的消化道酸性较低，无法溶解骨质物质。此外，SEM-EDS 分析表明其为肉食性，因此可能以鱼类为食。小型的旋曲形粪化石被认为是中生代旋曲形粪化石的第二次发现，其中可能含有植物花粉、完整的眶下骨、骨碎片簇和猎物的菱形硬鳞；并且在表面观察到生物侵蚀痕迹。我们推测那些旋卷两歧形足迹是由翼龙形类产生的，其猎物为楯齿龙形类，而旋曲形粪化石则代表了未分化鱼类的粪便，可能源自肉鳍鱼类。
