Fossils and Geological Eras

Fossils are the preserved remains or traces of organisms from a past geological age. The other options are too informal or inaccurate.

The K-T boundary (Cretaceous-Tertiary boundary) is a geological signature, usually a thin band of rock, that marks the end of the Cretaceous Period and the extinction of the dinosaurs.

Invasion of land by the first vascular plants occurred in this period.

The invasion of land by invertebrates like arthropods and marine arachnids.

Sphenodon, commonly known as the Tuatara, is a unique reptile found in New Zealand. It is the only surviving member of the order Rhynchocephalia and is often called a living fossil.

The Industrial Revolution, which triggered the modern explosion of science and technology, began roughly in the mid-18th century, placing the most significant developments within the last 200 to 250 years.

Radiometric dating, specifically using isotopes like uranium-lead, is the standard method for determining the age of the Earth.

Potassium-Argon dating is specifically used for dating volcanic rocks by measuring the decay of radioactive potassium into argon. This makes it the standard method for dating fossils embedded in volcanic layers, unlike radiocarbon which is limited to organic materials.

Bipedalism in early hominids is widely accepted to have emerged during the Miocene epoch, specifically associated with genera like Ardipithecus and early Australopithecus.

The Cenozoic is the current geological era, often called the Age of Mammals, which began approximately 66 million years ago.

 The whisk fern (Psilotum spp., family Psilotaceae) splays its leafless, whisk-like branches upward, and is a living fossil from the time before the dinosaurs. It can grow as an epiphyte in moist climates or as a terrestrial plant in drier areas. 

Fossils of pollen and microscopic spores are palynofossils.

In Pleistocene epoch the fossils of Sinanthropus pekinensis been discovered.

Fossils are the preserved remains, impressions, or traces of ancient plants and animals found within rock layers.

Archaeopteryx lithographia or the lizard bird is an extinct primitive bird that lived on earth about 150 million years ago.