TPO 43 Agnostids

The reading passage and lecture have conflicting opinions about how agnostids ate or how they behaved. The author claims that there are various theories on how agnostids may have lived. However, the lecturer refutes all arguments made by the author and she is of the opinion that the author's theories about agnostids have a serious weakness.

First and foremost, the author adamantly delineates that the agnostids may have been free-swimming predators. Nevertheless, the lecturer offsets these points by declaring that all anthropods have large eyes so that they can track its prey. On the other hand, the agnostids had tiny, poorly developed eyes. If they did chase after their predators, they would have had some special sensory organs to find their prey. But none of the evidence suggests that this would have been possible.

Secondly, according to the author of the excerpt, the agnostids may have dwelled on the seafloor. In the article, it is stated that they would have survived on the seafloor by scavenging dead organisms. In contrast, the professor explains that animals on seafloor do not have the ability to move fast. They move slowly and stay in the localized area. Moreover, they occupy a smaller area where they have originated. Whereas, agnostids were able to move from one place to the other area quickly. In addition to this, long distances would be very unusual for seafloor-dwellers.

Lastly, the article asserts that there is much possibility that the agnostids were parasites, who live and feed on larger organisms. On the other hand, the speaker of the listening says that the parasite population is not large enough. In other words, if there were too many parasites live on their host, they would kill off their host organisms. Whereas, the agnostids were not large because many species have been able to find a vast amount of fossilized individuals.