Trilobite Family Diversity over the Paleozoic Era. Although trilobites are the signature organism of the Paleozoic, first appearing in the Early Cambrian, their peak diversity was in the early Paleozoic, and they began a general decline in the upper Paleozoic (despite bursts of adaptive radiations in the Ordovician, Silurian, and Devonian periods), and that ended with their extinction in the ...Much like modern-day arthropods, trilobites had more than two eyes. (Image credit: Merlinus74 via Getty) Trilobites, a group of extinct marine arthropods, had a hidden third eye — and sometimes ...Define trilobite. trilobite synonyms, trilobite pronunciation, trilobite translation, ... Any of numerous extinct and mostly small arthropods that lived during the Paleozoic Era. …Kingdom: Animalia Phylum: Arthropoda Latreille, 1829 Class: Trilobita Walch, 1771 Order: Redlichiida Richter, 1932 ...It was at the end of the Paleozoic Era that the trilobite disappeared. For years the trilobite's extinction had been blamed on a sudden increase in the numbers of trilobite predators . … Other theories linked to trilobite extinction include climate change, sea-level fluctuation, and even the effects of meteorite impact.Unique Geology Era stickers featuring millions of original designs created and sold by independent artists. Decorate your laptops, water bottles, notebooks and windows. White or transparent. 4 sizes available.In today’s fast-paced business world, it’s essential to stay up-to-date with the latest trends and technologies. The term “new eras” refers to the constant changes and advancements that businesses face, from technological innovations to shi...Brachiopods, Fossils, Rocks, Fossils & Minerals, Collectibles. Shop the Largest Selection, Click to See! Search eBay faster with PicClick. Money Back Guarantee ensures YOU receive the item you ordered or get your money back.Dec 8, 2022 · Trilobites are a extinct group of marine arthropods that lived throughout the lower Paleozoic era. The first trilobites appeared during the early Cambrian period, and the last surviving species died out in the Permian–Triassic extinction event. Trilobites are one of the most diverse and successful groups of early animals, with over 20,000 ... 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. The trilobite exoskeleton was mineralised, constructed of calcite.High quality Paleontology Era-inspired gifts and merchandise. T-shirts, posters, stickers, home dec...Trilobites. Trilobites are extinct arthropods. Usually, only the skeleton is found as a fossil, and is rarely complete. The skeleton covered the upper side of the body and has a head (cephalon) and a tail (pygidium) separated by a flexible, jointed thorax. The skeleton is also divided length-wise into three lobes (giving trilobites their name ...Find many great new & used options and get the best deals for Fossil Trilobite Ceraurus Pleurexanthemus Ordovician Era Quebec Canada at the best online ...Jul 10, 2023 · Origen y evolución de los trilobites. El origen de los trilobites ocurrió en la era del Cámbrico, concretamente al principio del periodo del Paleozoico, hace mas de 500 millones de años. En esta época los organismos de la época Ediacarica se habían extinguido. Estos animales empezaron a diversificarse, desarrollarse y evolucionar durante ... HIDE SOLD. 42 Items ($145 to $545) Rare, Enrolled Encrinurus Deomenos Trilobite - Quebec. $545 $395. .83" Greenops Trilobite - Hungry Hollow, Ontario. $225. Two Flexicalymene Trilobites With Ceraurus - Belleville, Ontario. $195 $145. .9" Greenops Trilobite - Arkona, Ontario.Trilobites. Trilobites are extinct arthropods. Usually, only the skeleton is found as a fossil, and is rarely complete. The skeleton covered the upper side of the body and has a head (cephalon) and a tail (pygidium) separated by a flexible, jointed thorax. The skeleton is also divided length-wise into three lobes (giving trilobites their name ... Generally, the eras used to describe the modern Earth are the Quaternary geological era and the Cenozoic evolutionary era. In the future, there may also be a historical era that the current time period, the 21st century, will belong to.Hurdia victoria has been nicknamed the Tyrannosaurus rex of the Cambrian era due to its large size. Some specimens reached 50 cm (around 20 inches), which was large for a time when most animals were about as big as a fingernail. Its prey consisted of the first fossil in this slideshow, the trilobite, and other smaller animals crawling on the ... HIDE SOLD. 42 Items ($145 to $545) Rare, Enrolled Encrinurus Deomenos Trilobite - Quebec. $545 $395. .83" Greenops Trilobite - Hungry Hollow, Ontario. $225. Two Flexicalymene Trilobites With Ceraurus - Belleville, Ontario. $195 $145. .9" Greenops Trilobite - Arkona, Ontario.৪ সেপ, ২০২০ ... The last few trilobite lineages were extinct by the end of the Paleozoic Era, 251 million years ago. All told, trilobites scuttled along the ...More than 500 different trilobite species have been found across Utah, in a broken band of Cambrian Period (570 to 500 million years old) limestones ...Nov 14, 2013 · The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period (521 million years ago), and they flourished throughout the lower Paleozoic era before beginning a drawn-out decline to extinction when, during the Devonian, all trilobite orders except Proetida died out. Trilobites are an extinct group of arthropods, distinguished by the following characters: a body built from a cephalon, thorax, and pygidium a body divided into three lobes, running from head to tail one pair of antennae The last trilobites went extinct about 245 million years ago, but they are well represented by the fossil record.Nov 14, 2013 · The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period (521 million years ago), and they flourished throughout the lower Paleozoic era before beginning a drawn-out decline to extinction when, during the Devonian, all trilobite orders except Proetida died out. The Cenozoic Era (66 million years ago through today) is the "Age of Mammals." Birds and mammals rose in prominence after the extinction of giant reptiles. Common Cenozoic fossils include cat-like carnivores and early horses, as well as ice age fossils like wooly mammoths. Caves can preserve the remains of ice-age animals that died in them or ...Abstract. A previously unreported calymenid trilobite, Gravicalymene bakeri sp. nov., is described herein from Late Ordovician (latest Eastonian, Katian) shales of the Gordon Group, Tasmania. This is the first record of Gravicalymene from the Ordovician of East Gondwana (Australasia), a genus which is otherwise relatively well-known from …Perfect as a paperweight, or simply to have on display. This Fossilised Hollardops Trilobite existed in the Devonian period approximately 350 million years ...Jul 11, 2022 · Un amplio campo de visión era una ventaja para los trilobites con ojos encaramados o turgentes. Ojo facetado del trilobite Eldredgeops rana crassituberculata de Ohio. Algunos trilobites miraban a través del modo más antiguo y extendido de visión de los trilobites: el ojo holocrotal. Photo about Closeup of a flexicalymene ouzregui trilobite fossil in sand. the fossil is from the ordovician era and about 450 million years old. Image of trilobite, phacopida, ordovician - 3589515917" Incredible Plate Of Large Struveaspis Trilobites - Jorf, Morocco. $3,750. 35" Plate Of Giant Asaphid (Platypeltoides) Trilobites - Morocco. $3,750. 14" Association Of Large Trilobites & Other Arthropods. $3,750 $3,000. 43" Asaphid Trilobite Mortality Plate - Impressive Display. $3,500. Cluster of Six Chlustinia Trilobites - Tazarine, Morocco.Descrição. Os trilobitas possuíam um exoesqueleto de natureza quitinosa que, na zona dorsal, era impregnado de carbonato de cálcio, o que lhes permitiu deixar abundantes fósseis. Seu nome (trilobita) é devido a presença de três lobos que podem ser visualizados (na maior parte dos casos) em sua região dorsal (um central e dois laterais). internship blog post
Of course, back in the Paleozoic - the roughly 300 million year age that ran from the Cambrian through the Permian, and which has become known in scientific circles as the Age of Trilobites - our planet looked far different than it does today.Jan 5, 2023 · Trilobites lived in ancient seas during the Paleozoic Era, but became extinct during the Permian Period. Trilobite fossils have been found in Ordovician, Silurian, Devonian, Mississippian, and Pennsylvanian rocks in Kentucky, but are perhaps most commonly found in the Ordovician and Silurian rocks. ১০ জুল, ২০১৬ ... These little guys survived through the Ordovician era only to perish during the series of Ordovician–Silurian extinction events that wiped out ...Devonian Period, in geologic time, an interval of the Paleozoic Era that follows the Silurian Period and precedes the Carboniferous Period, spanning between about 419.2 million and 358.9 million years ago.The Devonian Period is sometimes called the “Age of Fishes” because of the diverse, abundant, and, in some cases, bizarre types …Toward the end of the Paleozoic Era, the once-thriving trilobite tribe had been reduced to a scattering of species. And they, too, …Unique Paleontology Era clothing by independent designers from around the world. Shop online for tees, tops, hoodies, dresses, hats, leggings, and more. Huge range of colors and sizes.Unique Cambrian Life Posters designed and sold by artists. Shop affordable wall art to hang in dorms, bedrooms, offices, or anywhere blank walls aren't welcome.Trilobites fossil from Middle Ordovician Era. Selective focus — Stock Photo ... Predatory trilobite Hydrocephalus briareus from cambrian period — Stock Photo, ...35" Plate Of Giant Asaphid (Platypeltoides) Trilobites - Morocco. $3,750. 14" Association Of Large Trilobites & Other Arthropods. $3,750 $3,000. 43" Asaphid Trilobite Mortality Plate - Impressive Display. $3,500. 2.1" Hoplolichoides Trilobite - Top Quality Preparation. $3,295. Cluster of Six Chlustinia Trilobites - Tazarine, Morocco. 2003 1h 48m R. Comedy, Romance, Drama. 6.3 40% 44% 62%. Jerry Falk, an aspiring writer in New York, falls in love at first sight with a free-spirited young woman named Amanda. He has heard the phrase that life is like "anything else," but soon he finds that life with the unpredictable Amanda isn't like anything else at all. Directed By.৩০ আগ, ২০১৮ ... The oldest definitive trilobite fossils are from a group called the Redlichiida, known from the Early Cambrian Period. Their segmented bodies ...As the seas advanced and retreated over a span of about 350 million years (Paleozoic Era), the ... Al- though trilobite fragments are rather abun- dant in some ...how to write a memorandum of agreement
Unique Cambrian Era stickers featuring millions of original designs created and sold by independent artists. Decorate your laptops, water bottles, notebooks and windows. White or transparent. 4 sizes available.The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period (521 million years ago), and they ...Trilobites from Fossil Era Trilobite fossils are some of the most beautiful and collectible fossils in the world! There are countless species of trilobites. They make beautiful display and conversation pieces. Common ones make very affordable for gifts to fossil and paleontology enthusiasts.There were dramatic worldwide sea-level changes and oceanic turnovers (exchanges of bottom waters and surface waters) resulting in a moderate level of extinctions during the Period. The Silurian ended with a series of relatively minor extinction events linked to climate change. * The Silurian was named by Murchison in 1839 for the Silures, …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. The trilobite exoskeleton was mineralised, constructed of calcite. The trilobites may have gone extinct (along with 95% of marine species) during the mass extinction at the end of the Permian period, but that doesn’t mean that they were a failure. On the contrary, the trilobites survived for more than 250 million years (longer than the dinosaurs), and dominated seafloor ecosystems for much of this time.Chapter contents: Arthropoda –– 1. Stem-group Arthropods–– 2. Trilobita ←–– 3. Chelicerata –– 4. Mandibulata Fossil specimens of Eldredgeops crassituberculata from the Devonian of Ohio (USA). Image by James St. John; Creative Commons Attribution 2.0 Generic license.Introduction Trilobites are among the most well-known fossils, thanks in large part to their abundance ...Same as pretty much every exposure in West New York, the park's fossils belong to the Middle Devonian period (over 300 million years old). Apart from trilobites, you can find crinoids (sea lilies), starfish, shells, coral, snails, prehistoric crabs, and sometimes petrified wood from later periods and - rarely - paleozoic fish.Trilobites are a group of extinct marine arthropods that first appeared around 521 million years ago, shortly after the beginning of the Cambrian period, living through the majority of the Palaeozoic Era, for nearly 300 million years.anthony adams meme origin
Trilobites from Fossil Era Trilobite fossils are some of the most beautiful and collectible fossils in the world! They make beautiful display and conversation pieces, and can be very affordable gifts for fossil and paleontology enthusiasts. Fossil Era has a huge selection of top quality trilobites from many states and many countries.A class of extinct marine arthropod animals that occur in marine rocks from the Paleozoic Era.Shop Cambrian Life Hoodies and Sweatshirts designed and sold by artists for men, women, and everyone. High-quality, pre-shrunk heavy or lightweight fleece.The Paleozoic Era. The Cambrian Period: Following the Precambrian mass extinction, there was an explosion of new kinds of organisms in the Cambrian Period (544–505 million years ago).Many types of primitive animals called sponges evolved. Small ocean invertebrates called trilobites became abundant.. Two representatives of more than fifty modern …Trilobites are extinct marine arthropods that dominated the shallow seas of the Paleozoic era. They became extinct in a global disaster Penn Dixie visitors ...Trilobite. A Trilobite is an extinct arthropod. These creatures lived in the oceans until about 252 million years ago. Before their extinction, they persisted on Earth for an impressive 300 million years. Researchers place these extinct creatures in the taxonomic class Trilobita. Read on to learn about the Trilobite. American Museum of Natural History 200 Central Park West New York, NY 10024-5102 Phone: 212-769-5100. Open daily, 10 am–5:30 pm. Closed Thanksgiving Day and Christmas Day.Trilobite Family Diversity over the Paleozoic Era. Although trilobites are the signature organism of the Paleozoic, first appearing in the Early Cambrian, their peak diversity was in the early Paleozoic, and they began a general decline in the upper Paleozoic (despite bursts of adaptive radiations in the Ordovician, Silurian, and Devonian periods), and that ended with their extinction in the ... pygidium (tail-shield) It is also divided from side-to-side into a central axis, with two side regions (lobes) called pleurae. The word ‘trilobite’ refers to this side-to-side partition, rather than the cephalon, thorax and pygidium. The cephalon, thorax and pygidium are all divided into segments.At this time the earth's continents were all together in a supercontinent called Pangea. The last of the Trilobites exited in the Permian period around 251 ...Unique Cambrian Life Posters designed and sold by artists. Shop affordable wall art to hang in dorms, bedrooms, offices, or anywhere blank walls aren't welcome.Women's Cambrian Fossils dresses designed and sold by independent artists. Choose from A-line dresses in sizes XXS-4XL and T-shirt dresses in sizes XS-XXL.It was at the end of the Paleozoic Era that the trilobite disappeared. For years the trilobite's extinction had been blamed on a sudden increase in the numbers of trilobite predators . … Other theories linked to trilobite extinction include climate change, sea-level fluctuation, and even the effects of meteorite impact.High-quality Cambrian Life Wall Art designed and sold by artists. Shop unique custom made Canvas Prints, Framed Prints, Posters, Tapestries, and more.mba undergraduate
Nov 14, 2013 · The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period (521 million years ago), and they flourished throughout the lower Paleozoic era before beginning a drawn-out decline to extinction when, during the Devonian, all trilobite orders except Proetida died out. The Devonian* saw the peak of marine faunal diversity during the Paleozoic Era. New predators such as sharks, bony fishes and ammonoids ruled the oceans. Trilobites continued their decline, while brachiopods became the most abundant marine organism.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. The trilobite exoskeleton was mineralised, constructed of calcite.The Paleozoic Era is the second oldest era of our Earth's history. Paleozoic means "Ancient Life" and lasted 345 million years. This is the first era in which scientists have found numerous fossils. It began about 600 million years ago with the first trilobites, a small, shelled sea creature resembling a modern crab.2003 1h 48m R. Comedy, Romance, Drama. 6.3 40% 44% 62%. Jerry Falk, an aspiring writer in New York, falls in love at first sight with a free-spirited young woman named Amanda. He has heard the phrase that life is like "anything else," but soon he finds that life with the unpredictable Amanda isn't like anything else at all. Directed By.The four eras in the history of marketing are known as the production era, sales era, marketing era and marketing control, or relationship, era. Some analyses only include the first three of these.Trilobites. Introduction: One of the most well-known and diverse groups of fossil arthropods belong to the class Trilobita and occur in Paleozoic rocks all over the world. They were already abundant in the mid-Cambrian (524 million years ago), reached their peak of diversity at the end of the Cambrian, and finally disappeared from the fossil ... The location of the state of Tennessee. Paleontology in Tennessee refers to paleontological research occurring within or conducted by people from the U.S. state of Tennessee. During the early part of the Paleozoic era, Tennessee was covered by a warm, shallow sea. This sea was home to brachiopods, bryozoans, cephalopods, corals, and …The location of the state of Tennessee. Paleontology in Tennessee refers to paleontological research occurring within or conducted by people from the U.S. state of Tennessee. During the early part of the Paleozoic era, Tennessee was covered by a warm, shallow sea. This sea was home to brachiopods, bryozoans, cephalopods, corals, and …৩ সেপ, ২০২৩ ... ... Era from the Early Cambrian Period until the end of the Permian Period. ... trilobite stuck to the bottom of his foot. As Godzilla crossed Odo ...Trilobites are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period and they flourished throughout the lower Paleozoic before slipping into a long decline, when, during the Devonian, all trilobite ... A trilobite is a form of invertebrate marine life that lived more than 550 million years ago, but are now extinct. These hard-shelled prehistoric critters ...What were trilobites? Trilobites are a group of extinct marine arthropods that first appeared around 521 million years ago, shortly after the beginning of the Cambrian period, living through the majority of the Palaeozoic Era, for nearly 300 million years. austin. reavesOct 14, 2020 · Trilobite - PUB2921. Trilobites comprise an extinct class of marine arthropods that lived throughout the world’s oceans during the Paleozoic Era between 540 and 250 million years ago. They are one of the signature creatures of that era. Breviphillipsia sampsoni is considered a rare trilobite species. Picture of an illustration of a trilobite moving about on a cambrian period (400 million years ago) sea bottom. trilobites are a well-known fossil group of ...Trilobites from Fossil Era Trilobite fossils are some of the most beautiful and collectible fossils in the world! There are countless species of trilobites. They make beautiful display and conversation pieces. Common ones make very affordable for gifts to fossil and paleontology enthusiasts.Much like modern-day arthropods, trilobites had more than two eyes. (Image credit: Merlinus74 via Getty) Trilobites, a group of extinct marine arthropods, had a hidden third eye — and sometimes ...Origen y evolución de los trilobites. El origen de los trilobites ocurrió en la era del Cámbrico, concretamente al principio del periodo del Paleozoico, hace mas de 500 millones de años. En esta época los organismos de la época Ediacarica se habían extinguido. Estos animales empezaron a diversificarse, desarrollarse y evolucionar durante ...The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period (521 million years ago), and they flourished throughout the lower Paleozoic era before beginning a drawn-out decline to extinction when, during the Devonian, all trilobite orders except Proetida died out.Paradoxides. Paradoxides is a genus of large to very large trilobite found throughout the world during the Middle Cambrian period. One record-breaking specimen of Paradoxides davidis, described by John William Salter in 1863, [2] is 37 cm (15 in). The cephalon was semicircular with free cheeks ending in long, narrow, recurved spines.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. The trilobite exoskeleton was mineralised, constructed of calcite. Learn about the evolution of trilobites, the localities where their fossils proliferate, and browse a gallery featuring thousands of specimens. Ticket reservations are required. …Women's Cambrian Fossils dresses designed and sold by independent artists. Choose from A-line dresses in sizes XXS-4XL and T-shirt dresses in sizes XS-XXL.Trilobites were marine arthropods that existed over 300 million years ago in the depths of the ocean across the world. They first appeared in the Pre Cambrian era and quickly grew to form the most diverse species in the world, with over 20,000 subspecies and 10 different orders. They lived for 300-400 million years, surviving major mass ... Unique Fossil Era designs on hard and soft cases and covers for iPhone 13, 12, SE, 11, iPhone XS, iPhone X, iPhone 8, & more. Snap, tough, & flex cases created by independent artists.haitian background
Abstract. A previously unreported calymenid trilobite, Gravicalymene bakeri sp. nov., is described herein from Late Ordovician (latest Eastonian, Katian) shales of the Gordon Group, Tasmania. This is the first record of Gravicalymene from the Ordovician of East Gondwana (Australasia), a genus which is otherwise relatively well-known from …Trilobites. Introduction: One of the most well-known and diverse groups of fossil arthropods belong to the class Trilobita and occur in Paleozoic rocks all over the world. They were already abundant in the mid-Cambrian (524 million years ago), reached their peak of diversity at the end of the Cambrian, and finally disappeared from the fossil ...No trilobites survived the end-Permian Mass Extinction event 252 million years ago. New York has one of the best fossil records of trilobites in the world and over 300 different species have been found in Cambrian- to Devonian-aged rocks in the state. Like all living arthropods, trilobites had to molt, or shed, their exoskeleton to grow.Aug 22, 2023 · 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 the beginning of the Cambrian Period, about 542 million years ago, when they dominated the seas. Mar 18, 2021 · Trilobites are a diverse group of prehistoric marine invertebrate animals that first appeared around 521 mya (million years ago), during the Cambrian Period of the Paleozoic Era. Trilobites are among the most successful early multicellular animals and were present on Earth for over 250 million years (that’s many millions of years longer than ... Grand Canyon’s oldest trilobites are found in the Tonto Group, which is between 525 and 505 million years old. It includes the Tapeats Sandstone, Bright Angel Shale, and Muav Limestone. These fossils are arthropods, or joint-footed animals, with a segmented body of hinged plates and shields.Trilobites were marine arthropods that existed over 300 million years ago in the depths of the ocean across the world. They first appeared in the Pre Cambrian era and quickly grew to form the most diverse species in the world, with over 20,000 subspecies and 10 different orders. They lived for 300-400 million years, surviving major mass ... ৮ জুন, ২০২১ ... Trilobite animation - an arthropod from the Paleozoic Era. 1965. Added 3 years ago anonymously in animal GIFs. Source: Watch the full video ...Trilobites are a extinct group of marine arthropods that lived throughout the lower Paleozoic era. The first trilobites appeared during the early Cambrian period, and the last surviving species died out in the Permian–Triassic extinction event. Trilobites are one of the most diverse and successful groups of early animals, with over 20,000 ...carter rees baseball
High-quality Cambrian Fossils throw blankets designed and sold by independent artists. Available in three sizes. Perfect for your couch, chair, or bed. It's all nappening.Jan 30, 2021 · The first, Redlichia rex, was one of the largest known trilobites of the Cambrian Period — Frisbee-size in a world of tea saucers. It was “a walking tank,” he said. “A big, bad beastie.” Trilobites are an extinct group of arthropods, distinguished by the following characters: a body built from a cephalon, thorax, and pygidium a body divided into three lobes, running from head to tail one pair of antennae The last trilobites went extinct about 245 million years ago, but they are well represented by the fossil record.Nektaspida. Trilobites are hard-shelled, segmented members of the phylum Arthropoda and the class Trilobita that appear in the fossil record for almost 300 million years—from about 540 to 251 million years ago (mya). They existed throughout almost all of the Paleozoic era, flourishing in the earlier part of it and slowly declining in the ...The trilobites may have gone extinct (along with 95% of marine species) during the mass extinction at the end of the Permian period, but that doesn’t mean that they were a failure. On the contrary, the trilobites survived for more than 250 million years (longer than the dinosaurs), and dominated seafloor ecosystems for much of this time. Trilobite. Trilobites are extinct marine animals belonging to class Trilobita, a subdivision of the phylum Arthropoda, which includes the familiar insects, crabs, centipedes, millipedes, spiders, scorpions, and horseshoe crabs, among others. The name “trilobite” is derived from the three longitudinal divisions, or lobes, of the trilobite body.