背鳍很大的古鱼应该是Bananogmius
至於下颚伸出来的古鱼,不懂
我想起了,那个下颚伸出来的古鱼是SAURODON!
Mawsonia lavocati头骨
Aspidorhynchus译名应是盾吻鱼,和雀鳝没任何关系,生存於侏罗纪至白垩纪
Aspidorhynchus (meaning "shield snout") is an extinct genus of ray-finned fish from the Jurassic and Cretaceous periods. Fossils have been found in Europe and Antarctica.
Aspidorhynchus was a slender, fast-swimming fish, 60 centimetres (2.0 ft) long, with tooth-lined, elongated jaws. It also had heavy scales and a symmetrical tail. The upper jaw was longer than the lower jaw, ending in a toothless spike. Although it would have looked superficially similar to the present day gar, its closest living relative is actually the bowfin
Matt Friedman在最近一期《美国科学院院刊,网络版》上发表了《海洋硬骨鱼类生态在白垩纪末期的选择性灭绝》。
今天,那些有类似特点的大型掠食性硬骨鱼类,例如金枪鱼和尖嘴鱼类,都是衰落和接近灭绝的。
“今天同一件事发生在生态学相似的鱼类身上,这些种类一直都是大型掠食性动物”,Friedman说。现代鱼类的研究显示出,大型尺寸与大 型猎物的大小和低的数量增长率有关,而快速闭合的下颌的出现是为了捕食敏捷的猎物,换句话说,是其他鱼类的捕食适应。化石记录提供了支持这些理论的一些不 同寻常的证据:它们胃里保存的鱼类化石。
科学家推测在白垩纪时灭绝的掠食性鱼类比其他鱼类更容易灭绝,因为它们的数量增长缓慢,活动范围更大,花费很多时间成熟,并且处于在食物链上不稳定的位置。今天,这些生态学上相似的鱼类看来,最难从过度捕捞恢复过来。
讽刺的是,今天这些敏捷的大型掠食性鱼类是在白垩纪的大型掠食性鱼类灭绝之后演化出来的,显然填补了它们的功能和生态学位置。虽然这两类鱼类之间没有关系,但是它们命运的结局很可能是相似的。
再贴一些有意思的白垩纪鱼类:
Gillicus,一种滤食性鱼类
The microscopic teeth of the Gillicus suggest it was a filter feeder that ate zooplankton, similar to today's baleen whales.