Fossils and Geological Eras

• Modern taxonomy is based on the hypotheses' of the evolutionary history of organisms, known as Phylogeny. As with the scientific method, scientists develop a hypothesis on the history of an animal and utilize modern science and technology to prove phylogeny.
• With the advent of such fields of study as phylogenetics, cladistics, and systematics, the Linnaean system has progressed to a system of modern biological classification based on evolutionary relationships between organisms, both living and extinct.
• So the correct option is 'phylogeny'.

About 3.8 billion years ago after the formation of earth, single celled prokaryotic cells (bacteria) appeared. It is supposed that the multicellular living organisms evolved from them. So, the correct option is B.

The first theory of evolution was proposed by Jean Baptiste de Lamarck. Lamarckism proposed:

Sphenopsida (like Calamites) were dominant in the Carboniferous period, not the Jurassic.

Sphenopsida are represented today by the genus Equisetum, so they are not extinct.

The Gymnosperms originated during the late paleozoic era but floursihed very well during mesozoic era. Hence, the mesozoic period is called as 'Age of Gymnosperms'.

During the Mesozoic era, specifically the Jurassic period approximately 200 million years ago, gymnosperms were the dominant land plants before the rise of angiosperms.

Olive Ridley sea turtles are often referred to as living fossils because their evolutionary lineage has remained largely unchanged for millions of years.

Sir Richard Owen, an English biologist and paleontologist, coined the term Dinosauria (meaning terrible lizard) in 1842.

The mass extinction event that wiped out the non-avian dinosaurs occurred approximately 65 to 66 million years ago at the end of the Cretaceous Period.

Dinosaurs first appeared during the Triassic Period (about 230 million years ago) and went extinct at the end of the Cretaceous Period (65 million years ago), spanning roughly 165 million years.

Sharks, crocodiles, and turtles have ancient lineages that date back to or before the time of dinosaurs. Bears, however, are mammals that evolved much later.

The earliest known dinosaurs appeared during the Triassic Period, roughly 230 million years ago.

The term dinosaur was coined by Richard Owen from the Greek words deinos (terrible or fearfully great) and sauros (lizard).

Mass extinctions are characterized by a sudden disappearance of many species from the fossil record, often indicating a catastrophic global event rather than a slow, gradual process.