PDF(Pubmed)
Abstract：
Pyritization of soft tissues of invertebrates is rare in the fossil record. In New York State, it occurs in black shales of the Lorraine Group (Late Ordovician), the best-known example of which is Beecher\'s Trilobite Bed. Exceptional preservation at the quarry where this bed is exposed allowed detailed examination of trilobite and ostracod soft-tissue anatomy. Here, we present the first example of a eurypterid (sea scorpion) currently ascribed to Carcinosomatidae from this deposit that also preserves the first evidence for mesosomal musculature in eurypterids. This specimen demonstrates that eurypterid musculature can be preserved in pyrite and evidences the oldest example of euchelicerate muscles within the fossil record. Sulfur isotope data illustrate that pyrite rapidly replicated muscle tissue in the early burial environment, prior to the pyritization of biomineralized exoskeleton and cuticular trilobite limbs. This discovery therefore expands the limited fossil record of euchelicerate musculature, while extending the taphonomic scope for preservation of detailed internal structures, more broadly, within arthropods.
摘要：
无脊椎动物软组织的黄化在化石记录中很少见。在纽约州,它发生在洛林组（奥陶纪晚期）的黑色页岩中，其中最著名的例子是比彻的三叶虫床。在暴露此床的采石场进行了出色的保存，可以对三叶虫和蛇形软组织解剖进行详细检查。这里,我们介绍了目前从该沉积物中归因于Carcinosomatidae的eurypterid（海蝎子）的第一个例子，该例子也保留了eurypterids中膜体肌肉组织的第一个证据。该标本表明，类动物肌肉组织可以保存在黄铁矿中，并证明了化石记录中最古老的euchelicerate肌肉的例子。硫同位素数据表明，黄铁矿在早期埋葬环境中快速复制肌肉组织，在生物矿化外骨骼和角质层三叶虫四肢的吡啶化之前。因此，这一发现扩大了euchelicerate肌肉组织的有限化石记录，同时扩展了保存详细内部结构的教学范围，更广泛地说，在节肢动物中。
