摘要
对盔甲鱼类研究中存在的若干问题进行了讨论:1)盔甲鱼类侧线系统的感觉管既不存在通向体表的上升管,迄今亦未发现其具通向体表的任何通道,所谓的感觉管裂隙,实乃假像。因此,其侧线如何与外在水体沟通和如何发挥功能仍是令人困惑的问题;2)网状安吉鱼Anjiaspis reticularis所谓的网状侧线系统,实系对皮下脉管丛(subaponeurotic vascular plexus)的误判,其真实的侧线系统目前仍不详;3)耿氏鸭吻鱼Gantarostrataspis gengi的侧线系统与华南鱼类和多鳃鱼类可作一对一对比,只是其唯一的一对中横管位置超前,未见于其他已知盔甲鱼类;4)巢湖汉阳鱼Hanyangaspis chaohuensis中所谓"腹片"和其上的侧线感觉管"腹侧沟"实乃不完整头甲背面和其上的裂隙,盔甲鱼类的腹片上迄今尚未发现感觉管的存在;5)盔甲鱼类是否存在松果孔长期存在争议,现查明是由于覆盖松果区的骨甲薄而易损毁,以致常现出松果孔存在的假象,真实的松果孔只存在于极少数种类。<正>在编写中国古脊椎动物志第一卷第一册无颌类盔甲鱼类这部分内容的过程中,我们对盔甲鱼类近50年的研究成果进行了系统梳理,对大量标本作了重新观察、照相和重绘复原图等基础性工作。在这个过程中,我们获得了一些新的认识,同时也发现不少需要商榷的问题。这些问题无法在志书中三言两语讲清楚,十分有必要专文加以讨论。为此,本文尝试从以下5例先行论述,作为对志书工作的一个有益补充。
The following fi ve problems in galeaspids are discussed in this paper.1） The lateral line canals of galeaspids differ from the typical ones of other vertebrates（Fig. 1） in the absence of the ascending tubes issuing from the canals to the surface of the headshield（Fig. 2B）, and no other passage from the sensory canals to the headshield surface（Figs. 2A, 3A1, 3A2） has been found yet. The slits of the lateral line canals in some galeaspids, such as Polybranchiaspis liaojiaoshanensis, which have been considered as the passages of the canals to the surface of the headshield（Janvier et al., 1993; Tong-Dzuy et al., 1995）, are proved to be a false appearance. As seen in Figs. 3B1, 3C1, some ridges are revealed along the courses of the sensory canals on the natural mould of the headshield of P. liaojiaoshanensis. These ridges were formed from the substance fi lled in the sensory canals during the fossilization of the creatures. The ridges, together with the superficial layer of the headshield covering the canals, adhere to the natural mould of the headshield, and result in the corresponding slits on the silicone rubber cast of the natural mould of the headshield（Figs. 3B2, 3C2）. If such ridges are removed from a natural mould of the headshield, the ornaments under the ridges will be clearly displayed on the natural mould, as seen in Fig. 3A1, and there will be no any slit in the silicone cast of the mould, as seen in Fig. 3A2. Therefore it remains unknown how the lateral line canals of gleaspids communicate with the current surrounding.2） The so-called lateral line canals of Anjiaspis reticularis revealed as ridges on the visceral surface of the headshield have been said to have a reticulation-like distribution which are mostly close to the pattern of the ancestral vertebrates（Gai and Zhu, 2005）. However, our reexamination indicates that these ridges are probably caused by vessels of subaponeurotic vascular plexus rather than sensory canals. In fact, both the sensory canals and the vessels of
出处
《古脊椎动物学报》
CSCD
北大核心
2014年第4期349-363,共15页
Vertebrata Palasiatica
基金
国家自然科学基金(批准号:41202015)
现代古生物学和地层学国家重点实验室(中国科学院南京地质古生物研究所)(编号:123101)资助
关键词
盔甲鱼类
侧线系统
松果孔
galeaspids
lateral line
pineal opening
