Crayfishes comprise a large and diverse group of freshwater lobster-like crustaceans. Despite being abundant in the recent, they are extremely rare in the fossil record. We revise a putative occurrence of Astacus multicavatusBell, 1863 from the marine Hauterivian of Speeton Clay (Speeton, United Kingdom), which was used a few years ago as a calibration fossil representing AstacusFabricius, 1775 for divergence time analyses. This species is actually a senior synonym to Eryma sulcatumHarbort, 1905. It so appears that Eryma multicavatum (Bell, 1863) comb. nov. is not a freshwater crayfish but a marine representative of Erymidae. Two co-occurring isolated chelae, also from the Speeton Clay, may correspond to larger, older specimens of E. multicavatum comb. nov.

中文翻译：

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Astacus multicavatus Bell, 1863 是一种海洋龙虾（十足目：Erymoidea：Erymidae），不是淡水小龙虾

小龙虾包括一大群种类繁多的淡水龙虾状甲壳类动物。尽管最近数量很多，但它们在化石记录中极为罕见。我们修改了来自 Speeton Clay（Speeton，英国）的海洋 Hauterivian 的 Astacus multicavatusBell 的假定出现，1863 年，它在几年前被用作代表 AstacusFabricius，1775 的校准化石，用于发散时间分析。这个物种实际上是 Eryma sulcatumHarbort, 1905 的高级同义词。看起来 Eryma multicavatum (Bell, 1863) 梳。十一月 不是淡水小龙虾，而是鲎科的海洋代表。两个同时出现的孤立螯合，也来自 Speeton Clay，可能对应于更大、更老的 E. multicavatum 梳子标本。十一月