Revision of Cyprinus maomingensis Liu 1957 and the first discovery of Procypris-like cyprinid (Teleostei, Pisces) from the late Eocene of South China

Abstract

Fossil cyprinids from the upper part of the upper Eocene Youganwo Formation of Maoming, Guangdong, China were first studied in 1957 by Liu, who referred the only specimen to the genus Cyprinus as a new species, C. maomingensis. And this was suggested as one of the earliest records for fossil cyprinids. Unfortunately, this specimen is poorly preserved and reveals no more morphological information than its serrated last unbranched dorsal and anal fin rays. Recently, some new specimens were unearthed from the same locality, where C. maomingensis was discovered. In addition to the serrated dorsal and anal fin rays, these new materials also show that the pattern and shape of their pharyngeal teeth obviously differ from that of Cyprinus but resemble that of Procypris. However, its number of the branched dorsal fin rays and number of vertebrae are much less than that in Procypris. Morphologically, these specimens are closer to Procypris than to Cyprinus. This is the first report of fossil Procypris-like fish, and it implies that Procypris-like fish is an early member of the Tribe Cyprinini sensu stricto (sensu Yang et al., 2010) and the origin of this group can be traced back at least to the late Eocene.

Evolutionary hotspot of Cenozoic fish: Paleogene ichthyofauna from the onshore basins around Beibu Gulf

“…该盆地的鱼化石, 除了刘宪亭 [1] 研究的一尾产自油柑窝组钻井岩芯中 的鲤科鱼化石外, 还有茂名石油公司于二十世纪六 七十年代发现的软骨鱼纲鲨鱼类(Selachii)的牙齿化 石. 近年来, 古脊椎所在该盆地油柑窝组新采集到一 批包括鲤科 [32] 和鲇形目在内的鱼化石.…”

“…本文所用亚科主要依据中国学者, 如伍献文 [49,50] Carassius carassius分布于欧洲 [46,48] . 古近纪的鲤亚 科化石目前仅见于本区域, 其中最早的是产自广东 茂 名 盆 地 上 始 新 统 的 茂 名 始 原 鲤 ( †Eoprocypris maomingensis) [32] . 1957年, 刘宪亭 [1] 研究了一尾产自 茂名盆地油柑窝组钻井岩芯中的鲤科化石, 将它归 入鲤亚科鲤属(Cyprinus), 定名为"茂名鲤( †Cyprinus maomingensis)", 并据此认为含鱼化石层的时代为中 新世.…”

“…实际上, 该标本保存欠佳, 除了末根不分枝 背、 臀鳍条均为具锯齿的硬棘这一鲤亚科特有的性状 外, 并无其他可归入鲤属的可靠特征 [38] . 近年, 古脊 名鲤"修订为茂名始原鲤 [32] . 产自印尼苏门达腊中部 始 新 世 的 始 鲤 属 †Eocyprinus, 曾 被 认 为 属 于 鲤 亚 科 [52] , 但其臀鳍末根不分支鳍条后缘不带锯齿、分支 鳍条有7根, 显然不可能属于末根不分支臀鳍条后缘 带 锯 齿 、 不 分 支 臀 鳍 条 一 般 仅 有 5 根 的 鲤 亚 科 [13] .…”

“…, and C standing for main row, outer row, and outmoster row of pharyngeal teeth, respectively. Tooth position is numbered from anterior to posterior in each row [13,32,51] 鲤亚科鱼类在渐新世有了明显分化, 如在宁明盆 地出现了粗棘花山鲤 †Huashancyprinus robustispina [13] , 在南宁盆地则有伍氏南宁鲤 †Nanningocyprinus wui [53] . 发 现 于 宁 明 盆 地 渐 新 统 宁 明 组 的 宁 明 生 态 鱼 †Ecocarpia ningmingensis [12] (图4), 鱼体细长而侧扁, 臀鳍基较长, 腹鳍骨分叉浅等特征与鲌亚科的相似; 但其咽齿侧扁, 主行齿有6或7枚, 明显不同于鲌亚科 而与鲴亚科的相似; 其背鳍第一根不分枝鳍条短, 且 与第二根不分枝鳍条相接触, 显然与鲌亚科和鲴亚 科 的 都 不 同 .…”

Changes in Extreme Low Temperature Events over Northern China under 1.5 °C and 2.0 °C Warmer Future Scenarios

“…Great progress has been achieved in research on extreme low temperature events under global warming in recent decades. Chen et al [14] pointed out that in future scenarios with different temperature thresholds, TN10p and TX10p show a certain decrease. That is to say, the frequency of occurrence of cold nights and cold days will be reduced, and the decrease will be greater with the increase of the threshold.…”