The study on the origin and evolution of sigillid ostracods characteristic of submarine caves

海底洞穴特征介形类起源与演化研究

• 批准号: 12640458
• 负责人: TABUKI Ryoichi
• 金额: $ 2.3万
• 依托单位: University of the Ryukyus
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12640458/
• 关键词: submarine caves; Sigillidae; ostracoda; coral reefs; hingement; adductor muscle scar; reversion; fossil record; Sigillidae(科); 起源; 進化; フィリピン海; 海溝; (貝形虫)殻; 付属肢; 洞窟壁

Sigillids are primitive podocopid ostracods having unequal valves and many small adductor muscle scars. The author found four troglobitic sigillid genera, Kasella Tabuki and Hanai 1999 and three new genera of Genus A, B and C, from coral reefs in the Pacific. In this study, the author taxonomically examined the carapace features of all the sigillid genera in detail and tried to demonstrate the phylogenetic affinities among the genera and the origin and evolution of the troglobitic sigillids.Sigillids are classified into two taxonomical groups for the presence of ornamentation: the non-ornate sigillids composed of Cardobairdia, Saipanetta and Genus A, and the ornate sigillids of Kasella, Genus B and Genus C. Cardobairdia is close to the ornate sigillids in having the 'original hingement' in the right valve. Saipanetta and Genus A differ from the other genera in having the 'two-layered hingement'. The ornate Genus B is closer to Cardobairdia in lateral outline and shape of adductor scar. Genus C shares many key carapace features not only with Kasella, but also with Genus B. While Kasella has many 'advanced carapace features', it shows the features possibly resulted from so-called reversion such as a posteroventral spine on the right valve appeared also in Cardobairdia and a primitive hingement structure similar to that of healdioideans.Only the non-troglobitic sigillids, Cardobairdia and Saipanetta, have the fossil records since the Jurassic. This fact suggests that the troglobitic sigillids derived from the non-troglobitic sigillids. The Genus A possibly derived from Saipanetta or its relatives. Genus B is thought to have originated from Cardobairdia or its relatives, Genus C from Genus B or its relatives and Kasella from Genus C or its relatives.

Sigillids是原始的podocopid介形类，具有不等的瓣膜和许多小的收肌疤痕。作者在太平洋珊瑚礁中发现了四个穴居的银螺属，Kasella Tabuki和Hanai 1999，以及三个新属A，B和C。在本研究中，作者详细地研究了所有属的背甲特征，并试图证明属间的系统发育关系以及穴居的背甲的起源和演化。由Cardobairdia、Saipanetta和A属组成的非华丽的印形虫和由Kasella、B属和C属组成的华丽的印形虫。Cardobairdia在右瓣有“原始铰链”方面接近华丽的印戒。塞帕内塔和A属与其他属的不同之处在于具有“双层铰链”。华丽属B在侧面轮廓和收肌痕形状上更接近Cardobairdia。C属不仅与Kasella，而且与属B共享许多关键的甲壳特征。虽然Kasella具有许多“先进的甲壳特征”，但它显示了可能由所谓的逆转导致的特征，例如Cardobairdia也出现在右瓣上的后腹刺和类似于healdioideans的原始铰链结构。只有非穴居的Sigillids，Cardobairdia和Saipanetta，有侏罗纪以来的化石记录。这一事实表明，穴居的Sigillids来自非穴居的Sigillids。A属可能来自塞帕内塔或其亲属。B属被认为起源于Cardobairdia或其近缘种，C属被认为起源于B属或其近缘种，而Kasella被认为起源于C属或其近缘种。

项目成果

Ryoichi Tabuki: "On the taxonomy and origin of sigillids characteristic of submarine caves of coral reefs"Abstracts of 14th International Symposium on Ostracoda. 89 (2001)

Ryoichi Tabuki：“关于珊瑚礁海底洞穴特征的印记的分类和起源”第14届国际介形类研讨会摘要。

Tabuki, R.: "On the taxonomy and origin of sigillids characteristic of submarine caves of coral reefs"Abstracts of the 14th International Symposium on Ostracoda. 89 (2001)

Tabuki, R.：“关于珊瑚礁海底洞穴特征的印记的分类和起源”第 14 届介形类国际研讨会摘要。