trilobite

noun

tri·​lo·​bite ˈtrī-lə-ˌbīt How to pronounce trilobite (audio)
: any of numerous extinct Paleozoic marine arthropods (group Trilobita) having the segments of the body divided by furrows on the dorsal surface into three lobes

Illustration of trilobite

Illustration of trilobite
  • trilobite fossil

Examples of trilobite in a Sentence

Recent Examples on the Web The synchrotron radiation imaging was detailed enough that the species that the trilobite had been eating could be identified. John Timmer, Ars Technica, 27 Sep. 2023 Utah, too, has one of the most complete fossil records on the planet, starting 2 billion years ago and featuring everything from mollusks to trilobites. Sofia Quaglia, Discover Magazine, 21 Dec. 2023 More than 20,000 species of trilobite lived during the early Cambrian to the end-Permian period roughly 541 to 252 million years ago. Laura Baisas, Popular Science, 27 Sep. 2023 The team speculates that the trilobite may have been molting, which could explain the feeding frenzy. Jack Tamisiea, Scientific American, 28 Sep. 2023 But one major aspect of trilobites’ ecology that had long eluded researchers was their diet. Jack Tamisiea, Scientific American, 28 Sep. 2023 These unknown creatures burrowed into this trilobite’s carcass and targeted its soft tissue, but avoided its gut. Laura Baisas, Popular Science, 27 Sep. 2023 The researcher demonstrated this scientific approach by licking a 400 million-year-old trilobite during his online acceptance speech. Catherine Nicholls, CNN, 15 Sep. 2023 All the site’s trilobites are also juveniles, suggesting that this could have been a nursery. Jack Tamisiea, Scientific American, 10 May 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'trilobite.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

borrowed from German Trilobit, from New Latin trilobus "three-lobed" (borrowed from Greek trílobos, from tri- tri- + -lobos, adjective derivative of lobós lobe) + German -it -ite entry 1

Note: German Trilobit was introduced by the theologian and naturalist Johann Ernst Immanuel Walch (1725-78) in Die Naturgeschichte der Versteinerungen zur Erläuterung der Knorrischen Sammlung von Merkwürdigkeiten der Natur ("The Natural History of Fossils, as a Commentary on the Knorr Collection of the Curiosities of Nature"), 3. Theil (Nuremberg, 1771) p. 120 and following. This work, in four parts issued from 1768 to 1773, was an expanded and greatly improved edition of a publication begun by the Nuremberg engraver and fossil collector Georg Wolfgang Knorr, who had died in 1761. According to Walch, "Da man dieses Petrefact Anfangs nur Stückweise entdeckte, und nicht wusste, zu was vor einer Gattung von Körpern man dasselbe rechnen sollte, so hielte sich fast jeder Naturforscher, der dasselbe bekannt machte, für berechtiget, ihm einen eigenen Nahmen beyzulegen …[there follows a discussion of various names, as concha trílobos [latter word in Greek letters], concha triloba rugosa, pectunculites trilobus, entomolithus paradoxus, Dudley fossil, etc.]…Alle aber, zusammen genommen, sind ihm gegeben worden, entweder von seiner Gestalt und Aenlichkeit, die es mit andern Körpern hat, oder von dem vermeintlichen Original, so man, wiewohl meist ohne Grund, dafür angesehen, oder von dem Ort und Gegend, wo man dasselbe gefunden. Wir wollen ihm die allersimpelste Benennung beylegen, und es einen Trilobiten nennen" ("Since early on only fragments of the fossil had been discovered, and no one knew the category of body under which it should be considered, almost every investigator of nature who made it known felt justified in conferring on it his own name …Taken together, all these names have been given either from its shape and similarity to other bodies, or from what is regarded, usually without any basis, as the presumed prototype, or from the place where it was found. We want to confer on it the simplest name possible, and call it a trilobite"). (Walch uses Trilobit as a weak noun, with an accusative singular Trilobiten.) Walch's Naturgeschichte der Versteinerungen was translated into Dutch (3rd Part, 1773) and French (3rd Part, 1775), with the animal designated respectively as Trilobiet and Trilobite in these languages. Further details about Walch, as well as an English translation of the French version of relevant passages from Naturgeschichte der Versteinerungen, can be found in Robert Kihm and James St. John, "Walch's Trilobite Research—A Translation of His 1771 Trilobite Chapter," Fabulous Fossils—300 Years of Worldwide Research on Trilobites, edited by D.G. Mikulic, et al., New York State Museum Bulletin 507 (Albany, 2007), pp. 115-40. Note that Walch only uses Trilobit as a vernacular designation; the class name Trilobita, though attributed to Walch in taxonomic literature, does not appear in the book.

First Known Use

1832, in the meaning defined above

Time Traveler
The first known use of trilobite was in 1832

Dictionary Entries Near trilobite

Cite this Entry

“Trilobite.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/trilobite. Accessed 29 Mar. 2024.

Kids Definition

trilobite

noun
tri·​lo·​bite ˈtrī-lə-ˌbīt How to pronounce trilobite (audio)
: any of a group of extinct invertebrate animals that lived in Paleozoic seas, have a body composed of segments and divided lengthwise along the back into three parts, and are classified as arthropods

More from Merriam-Webster on trilobite

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!