CategoriesFossils
by 0

Fossils are echoes of an ancient past

Fossils are echoes of an ancient past. Find out about the two major categories of fossils, how fossilization occurs, and how fossils can help paint a picture of the planet’s history.

A fossil (from Classical Latin: fossilis, literally ‘obtained by digging’) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood, oil, coal, and DNA remnants. The totality of fossils is known as the fossil record.

 

Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absolute ages of rocks and the fossils they host.

 

There are many processes that lead to fossilization, including permineralization, casts and molds, authigenic mineralization, replacement and recrystallization, adpression, carbonization, and bioimmuration.

 

Fossils vary in size from one-micrometre (1 µm) bacteriato dinosaurs and trees, many meters long and weighing many tons. A fossil normally preserves only a portion of the deceased organism, usually that portion that was partially mineralized during life, such as the bones and teeth of vertebrates, or the chitinous or calcareous exoskeletons of invertebrates. Fossils may also consist of the marks left behind by the organism while it was alive, such as animal tracks or feces (coprolites). These types of fossil are called trace fossils or ichnofossils, as opposed to body fossils. Some fossils are biochemical and are called chemofossils or biosignatures.

CategoriesDinosaurs
by 0

Mosasaurs were Earth’s last great marine reptiles

MOSASAURUS BEAUGE

Cretaceous age (- 66 millions years old)

Mosasaurs were Earth’s last great marine reptiles. Learn about the surprising places they’d hunt, how some species dwarfed even the Tyrannosaurus rex, and how key physical adaptations allowed these reptiles to become a prehistoric apex predator.

Discovery and identification

The first Mosasaurus fossil known to science was first discovered in 1764 in a chalk quarry near Maastricht, the Netherlands in the form of a skull, which was initially identified as a whale.Later around 1780, the quarry produced a second skull that caught the particular attention of the physician Johann Leonard Hoffmann, who thought it was a crocodile. He contacted the prominent biologist Petrus Camper, and the skull gained international attention after Camper published a study that identified it as a whale. This caught the attention of French revolutionaries, who looted the fossil following the capture of Maastricht during the French Revolutionary Wars in 1794. In a 1798 narrative of this event by Barthélemy Faujas de Saint-Fond, the skull was allegedly retrieved by twelve grenadiers in exchange for an offer of 600 bottles of wine. This story helped elevate the fossil into cultural fame, but historians agree that the narrative was exaggerated.

 

After its seizure, the second skull was sent to the National Museum of Natural History, France in 1795 and later cataloged as MNHN AC 9648. The animal, which by then was nicknamed the “great animal of Maastricht,” was found by Camper’s son Adriaan Gilles Camper and Georges Cuvier by 1808 to belong to a marine lizard with affinities to monitor lizards, but otherwise unlike any modern animal. The skull became part of Cuvier’s first speculations about the conception of extinction, which later led to his theory of catastrophism, a precursor to the theory of evolution. At the time, people did not believe that a species could go extinct, and fossils of animals were often interpreted as some form of an extant species.

 

Cuvier’s idea that there existed an animal unlike any today was revolutionary at the time, and in 1812 he proclaimed, “Above all, the precise determination of the famous animal from Maastricht seems to us as important for the theory of zoological laws, as for the history of the globe.” William Daniel Conybeare coined the genus Mosasaurus in 1822, and Gideon Mantell added the specific epithet hoffmannii in 1829. Cuvier later designated the second skull as the new species’ holotype.

CategoriesDinosaurs
by 0

Pterosaurs were the first vertebrates to take to the skies

COLOBORHYNCHUS MOROCCOENSIS

Cretaceous age (- 136 millions years old) 

Pterosaurs were the first vertebrates to take to the skies. Learn about the anatomical features that made their flight possible, how large some of these creatures grew, and which species was named after a vampire legend.

Coloborhynchus is a genus of pterodactyloid pterosaur belonging to the family Anhangueridae, though it has also been recovered as a member of the Ornithocheiridae in some studies. Coloborhynchus is known from the Lower Cretaceous of England (Valanginian age, 140 to 136 million years ago) and depending on which species are included, possibly the Albian and Cenomanian ages (113 to 93.9 million years ago) as well. Coloborhynchus was once thought to be the largest known toothed pterosaur, however, a specimen of the closely related Tropeognathus is now thought to have had a larger wingspan.

 

Like many ornithocheiroid pterosaurs named during the 19th century, Coloborhynchus has a highly convoluted history of classification. Over the years numerous species have been assigned to it, and often, species have been shuffled between Coloborhynchus and related genera by various researchers.

.

CategoriesDinosaurs
by 0

10 Biggest Sea Dinosaurs That Ever Existed on Earth

Whatever lives in the sea nowadays can’t be compared with the huge monsters that dominated the depths millions of years ago. And by “monsters” we mean long-extinct marine reptiles and dinosaurs. Since many people are better acquainted with the land-roaming giants of the past, this video will open your eyes to those that ruled the waters! Did you know, for example, that pliosauruses were real giants, with the largest species weighing more than 30 tons and growing up to 40 feet long? Also, this animal had an incredibly strong bite. In fact, it was four times more powerful than that of the mighty T-rex! 

10 Biggest Sea Dinosaurs:

  • Pliosaurus 
  • Kronosaurus
  • Nothosaurus
  • Styxosaurus
  • Albertonectes
  • Thalassomedon
  • Tylosaurus
  • Shonisaurus
  • Mosasaurus
  • Shastasaurus