Trilobites are also a representative invertebrate. It is an extinct arthropod. Its entire body is divided into three parts: the head, thorax and tail. Its shell is hard and divided into three approximately equal pieces by two deep longitudinal grooves. They lived in ancient oceans, appeared mainly in the Cambrian, and persisted until their disappearance at the end of the Permian. Trilobites can both swim and crawl, so everything from the sea floor to the surface is within its sphere of influence.
When Earth entered 543 million years ago, marine invertebrates suddenly flourished, and one of the most successful animals was called trilobites. Trilobites were the most numerous animals in the ocean at that time and their biomass represented approximately 60% of the biomass of macroscopic animals in the entire ocean. This situation lasted until 410 million years agoborn. Therefore, 543 million to 410 million years ago is called the age of trilobites. The Trilobite Age, the Lower Paleozoic era in geological history, is divided into three periods: the Cambrian (543 million to 490 million years ago), the Ordovician (490 million to 438 million years ago) and the Silurian (438 million to 410 million years ago). years ago).
Koneprusiasp.
Neoasaphus kowalewski
Acadoparadoxides briareus
Harpides sp.
Dechenella lucaensiss
The reason trilobites were able to dominate the entire early Paleozoic era for a long period of 133 million years was because they had an extraordinary ability to compete for survival. On average, they are only 5 to 6 centimeters long and 3 to 4 centimeters wide. Although it is only one ten millionth the size of dinosaurs, its ability to survive and compete is tens of millionsns times stronger than that of the dinosaurs. For example, some trilobites are covered in thorns to prevent them from being eaten by other animals; some trilobites bury themselves in the soft mud of the seabed and extend their long eyes to observe so as not to be discovered by their natural enemies. situation ; some encounter natural enemies, and their bodies immediately roll up and fall to the seafloor... In May 2009, Portuguese geologists discovered numerous large trilobites in the 465 million year old strata in northern Portugal, the largest is 90 centimeters long, making it the largest trilobite ever discovered. Additionally, they discovered a group of more than 1,000 trilobites, indicating that trilobites may be creatures that mate in groups, give birth to large numbers of offspring, and win by their sheer numbers. Therefore, trilobites are a kind of ins“long-lived” ect. They went from the beginning of the Paleozoic to the end of the Paleozoic (410 million to 250 million years ago). However, when they entered the Devonian period of the late Paleozoic (410 million to 354 million years ago), they flourished and then declined. But trilobites are very “strong” and survive despite their decline. They crossed three periods of the Upper Paleozoic: the Devonian, the Carboniferous (354 million to 295 million years ago) and the Permian (295 million to 250 million years ago). They were not completed until the end of the Permian. . Trilobites' rise fromExtinction lasted the entire Paleozoic era, or 293 million years.
Restoration Map of Trilobite Era Organisms
In the Trilobite Era, in addition to arthropod trilobites, other common macroscopic marine invertebrates included graptolites (a type of small worm-like animals), brachiopods, gasteropods, corals, nautiluses, soft-tongued snails, bryozoans, etc. Among marine vertebrates, the oldest fish appeared, such as Kunming fish and Haikou fish. Fish, like jawless fish, first appeared in terrestrial waters. After the decline of trilobites, the history of the Earth entered another era: that of fish.
The largest trilobite discovered in Portugal
Restoration map of the Ordovician biota
Ammonites and orthogonal fossils from the Ordovician
< p>Ordovician graptolite fossils