The reading passage and the lecture hold conflicting opinions about the agnostids were a group of marione animals that became extinct about 450 million years ago. The article argues that the passage opinion. However, the lecture disagrees. 

First, the reading passage claims that the Agnostids is free-swimming predators.And while the agnostids were small, sometimes just six millimeters long, there were plenty of smaller organisms in the ancient ocean for them to prey on. However, the lecture contradicts it. 

Second, the reading passage states the Agnostids is Seafloor Dwellers, there are examples of other types of primitive arthropods living this way. On the seafloor they would have survived by scavenging dead organisms or by grazing on bacteria. On the contrary, the lecture opposes it.

Finally, the reading passage maintains that the Agnostids is Parasites, living on and feeding off larger organisms. The agnostids might have lived on primitive fish or even on other, larger arthropods. However, the lecture disagrees wth it.