Fossils are familiar to most of us as the hardened, three-dimensional remains of ancient plants and animals, whose tissues have been impregnated by, or replaced with, minerals such as calcite, iron, and silica, thus arresting their inevitable decay. Because the mineralization process results in a rock that’s usually harder than the material around it, especially in the case of petrification, fossils are durable snapshots of the past.

But the universe of fossils also includes the impressions of such organisms, like the outline of a leaf preserved on a layer of slate, or the footprint of an animal left in mud that then filled in with sandy sediment, thus capturing this trace of the animal’s fleeting time on earth.

Collectors of fossils have an extraordinary number of pieces to choose from. Invertebrate fossils range from sponges and corals to trilobites and ammonites, the later of which were wiped out some 66 million years ago when an asteroid about six miles wide and traveling 45,000 miles per hour plowed into what is now the Yucatan peninsula, vaporizing pretty much everything on the surface of North America in about two minutes and causing the extinction of about 75 percent of the rest of the planet’s life forms in the years that followed.

Vertebrate fossils include fish, whether it’s the delicate outline of a perch or a single menacing shark’s tooth, as well as the bones of birds, reptiles, amphibians, mammals, and, yes, dinosaurs, which joined the ammonites in the planet’s last great die-off, prior to the one we’re in right now.

Trace fossils are particularly interesting. In addition to prints, trace fossils includes borings and burrows. Chondrite fossils are often mistaken for plant fossils because they resemble the branching stems of a conifer or perhaps delicate roots. In fact, they are the remains of burrows created by roundworms. Another group of invertebrates that resemble plants are graptolites, which can look like leaves (retiolites) and fanlike ferns (rhabdinopora).

Crustacea are favorites because of their familiar shapes (crabs, shrimp), as are bivalves, mollusks, and insects—for some people, the shape of a fossilized dragonfly is not only visually appealing, but also seems a link between ancient and modern times.

Still, bones are the prize, especially those of diapsid reptiles such as the megalania, which lived in Australia during the Pleistocene epoch and was the larger (20-foot-long) forebear of the Komodo Dragon. More common are the teeth and other remains of equus, the ancient cousin to the contemporary horse.

Best of the Web (“Hall of Fame”)

National Carousel Association

National Carousel Association

Since 1973, the National Carousel Association has been dedicated to preserving and restoring carousels and carousel… [read review or visit site]

Most watched eBay auctions    

Dinosaur, Leg-bone (fibula) Of Edmontosaurus, Hell Creek FossilDinosaur, Edmontosaurus, Composite Toe, Fossil, Hell CreekImpressive Jaw Of A Woolly Rhinoceros With One Tooth Fossil Pleistocene Ice AgeBig & Tough 4 1/8" Megalodon Shark Tooth Teeth Extinct Megladon Jaw Fossil Monster * 6 Inch * Megalodon Fossil Shark Tooth - South Carolina4 11/16'' Megalodon Tooth, Very Nice! /fossil Sharks TeethImpressive Jaw Of A Megaloceros Giganteus(irish Elk) Fossil Pleistocene Ice AgeMuseum Quality Olenellus Trilobite Fossil! Fine Complete Ameropiltonia Lauradanae Trilobite L. Carboniferous,missouri, Usa4 5/8" Classic Megalodon Shark Tooth Teeth Extinct Megladon Jaw Fossil Sharp5.894" Megalodon Tooth Fossil Extinct Prehistoric Shark Teeth Large Fossilized Petrified Wood Log 13 Lbs With Unique Knot HolesSis: Most Unusual Petrified Wood Round, Mcdermitt, Or - Super Agatized!5.678" Megalodon Tooth Fossil Extinct Prehistoric Shark Teeth Huge Rooted Mastodon Tooth Florida Fossils Fossil Teeth Jaw Bone Bones Mammal FlHuge 4 15/16" Megalodon Shark Tooth Teeth Extinct Jaw Fossil MegladonMonster Nearly 6" Megalodon Shark Tooth FossilMassive 5 1/2" Megalodon Shark Tooth Teeth Jaw Fossil W/display.megladonSis: Emerald Green Framed African Petrified Wood Round - Ultra-rare Woodworthia!Rare Trilobite, Proetus Concinnus, Silurian, Gotland, Sweden (eb2336)Sis: Chinle Fossil Woodworthia Petrified Wood Display Specimen -northern ArizonaMassive 5 5/8'' Megalodon Fossil Sharks Tooth, Impressive!Fossil Trilobite Eldredgeops Crassituberculata From Paulding, Ohio. ClosedSis: Perfect 4.3 Lb. Petrified Wood Log - Dramatic African Woodworthia!Nicely Serrated 5 3/16'' Megalodon Fossil Sharks ToothSis: Immaculate 4.6 Lb. Hoodoo Creek Petrified Log - Very RareSis: Phenomenal 16" Hubbard Basin Petrified Wood Round! 10 Lb. Heel - My Best!Large, Polished Colorful Arizona Petrified Wood RoundAsaphus Gracilis Trilobite Russia No RestorationImpressive Horn Of A Megaloceros(irish Elk) Fossil Pleistocene Ice AgeBeautiful Multiple Crinoid Dimerocrinites Sp. L.silurian, Llandovery, Anticosti 4.3" Whole Ammonite Fossil Sutured Patterns - Madagascar83 Million Year Old Xiphactinus Jaw From The Niobrara Chalk Of Kansas2795ct 100% Natural Iridescent Ammonite Ammolite Rough Specimen Fossil Yan51761471.5ct 100% Natural Iridescent Ammonite Ammolite Rough Specimen Fossil Yan5180Fine Complete Pyritised Minicryphaeus Sp. : Lower Devonian Of MoroccoFossil Dinosaur Tyrannosaur Daspletosaur Skull Tooth Montana Russian Trilobite Asaphus Lepidurus (nieszkowski 1859)Rare Eurypterid Sea Scorpion - Trilobite AgeDinosaur, Oviraptorsaur Manus Claw, Likely Anzu Wyliei, Fossil, Hell CreekRussian Trilobite Asaphus Lepidurus (nieszkowski 1859) For Preparation. Albertosaurus Tooth Dinosaur Fossil RareAuthentic Fossil Starfish Petraster Sp. Ordovician - Ktaoua Formation, MoroccoSis: Stunning Fossil Wood Grain Eden Valley Wyoming Petrified Wood Round!Massive 5.10" Megalodon Tooth Fossil Shark Teeth Natural Carolina Big C765Echinoid With Spicules Gymnocidaris Koechlini In Matrix Plesiosaurus Bone Sis: Hampton Butte - 12" Red & Green Petrified Wood Round - Rare Live OakChirostenotes Claw, Hell Creek Find3275.5ct 100% Natural Iridescent Ammonite Ammolite Rough Specimen Fossil Yan5175Mm259 4.56" No Reserve Calico Megalodon Shark Tooth South CarolinaComplete Branchiosaur Amphibian Apateon Pedestris Permian Of GermanyTrilobite Fossils Redlichia (redlichia) Mansuyi, Professional Collection3-3/8" Polished Tooth Megalodon Shark Prey. " Whale Wars " Best Of The Best Double Porpita Sp. Candidate Cnidarian; Vendian Of Western AustraliaRussian Trilobite Asaphus Lepidurus With Imprint For Preparation . 4.1" Polished Fossil Coral Specimen - Devonian Age - MoroccoDysplanus Babinoensis Trilobite Russia Fine 1% RestorationHuge, Polished Arizona Petrified Wood RoundRare Valuable Miocene Amphibian Frog Fossil With Whole Skeleton Skull FossilHuge 5.01" Megalodon Tooth Fossil Shark Teeth Natural Big Carolina C749