Trilobites (/ ˈ t r aɪ l ə ˌ b aɪ t s, ˈ t r ɪ l ə-/; [4] [5] [6] meaning "three-lobed entities") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest known groups of arthropods.

2025年1月8日 · trilobite, any member of a group of extinct fossil arthropods easily recognized by their distinctive three-lobed, three-segmented form. Trilobites, exclusively marine animals, first appeared at 521 million years ago near the beginning of the Cambrian Period (538.8 million to 485.4 million years ago), when they dominated the seas.

2024年10月25日 · Some of the most striking invertebrate fossils present in national parks are those of arthropods. Trilobites are probably the most beloved marine invertebrate fossils, and fossils of insects are a source of wonder because of their delicate features and rarity.

2023年7月5日 · What are trilobites? Trilobites were a diverse group of extinct marine arthropods that lived from the Cambrian to the Permian periods. They had a hard exoskeleton divided into three lobes, hence the name “trilobite.” When did trilobites exist?

Among famous groups of extinct organisms, trilobites probably rank second only to the dinosaurs in fame. Their fossils are instantly recognizable and often strikingly beautiful. In fact, prehistoric people liked them as much as we do.

Trilobites are a well-studied group of organisms, yet their relationship to other arthropods is uncertain. Along with several other taxa with similar appearances, including the vicissicaudata that are introduced below, trilobites are often placed in the arthropod group Artiopoda.

Trilobita is the most species-rich entirely extinct arthropod group. In trilobites, the hard exoskeleton covering the dorsal body surface and its well marked segmentation (for example, the jointed segments of the thorax) are classic arthropod features.

Trilobites comprise a complex and huge clade of arthropods with estimates of number of species ranging up to 20,000 thousand among some 5000 genera, 150 families, and nine distinct orders.

2023年5月16日 · Trilobites are extinct arthropods, the animal group that today includes insects, centipedes, crustaceans, spiders, scorpions, and more. All trilobites lived in the ocean. Most crawled on the seafloor, but others swam.

2020年3月23日 · Trilobites belong to the phylum Arthropoda. They share the characteristics of arthropods with other members of the phylum, including insects , arachnids , crustaceans, millipedes , centipedes , and horseshoe crabs.