Fish evolved 530 million years ago. The lobe-finned fish are considered the ancestors of tetrapods (four-legged animals) and emerged around 400 million years ago.
The Triassic–Jurassic extinction cleared ecological space for dinosaurs to become the dominant land animals of the Jurassic.
Triassic–Jurassic Extinction: Volcanoes Open the Age of Dinosaurs Read More »
The Devonian extinction shows that evolution can be reshaped not by one sudden blow, but by a long collapse in ocean health.
Oceans Lose Their Breath Read More »
The Ordovician–Silurian extinction shows how climate change can reshape evolution by collapsing old ecosystems and opening space for new life.
Ordovician–Silurian Extinction: Ice Strikes the Seas Read More »
Snowball Earth was a time when our planet may have frozen nearly from pole to pole, testing life and setting the stage for later biological change.
Snowball Earth: When Ice Reached the Equator Read More »
The animal evolution of the bilaterian body plan is directionality, which gave us agency.
Bilaterian Split: The Origin of Agency Read More »
Before, during, and after the K–Pg extinction: a thriving Late Cretaceous world of dinosaurs, pterosaurs, birds, and flowering plants gives way to the asteroid strike and global collapse that ended the age of non-avian dinosaurs.
The K-Pg Extinction Read More »
The Permian-Triassic extinction was not just the end of many species. It was a planetary reset that destroyed the old synapsid-dominated world and opened the door for the archosaur line that would later give rise to dinosaurs.
The P-T Extinction Read More »
About 255 million years ago, during the late Permian, our mammalian ancestory, the synapsids ruled the land.
The Synapsid World of the Late Permian Read More »
The Cenozoic era starts with the K–Pg extinction 66 million years ago. That event marks the sudden end of the reign of dinosaurs and the rise of mammals and birds.
Cenozoic Era: Age of Mammals & Birds Read More »
The Mesozoic era starts with the end-Permian mass extinction 252 million years ago. Dinosaurs ruled over all, including us. It ends the reign of dinosaurs with the K–Pg extinction 66 million years ago.
Mesozoic Era: Age of Dinosaurs Read More »
The start of the Paleozoic era is marked by burrowing life 538.8 million years ago. The era includes the dominant rise of our ancestors. It ends 252 million years ago with the end-Permian mass extinction, a volcanic cascade global warming event.
Paleozoic Era: The Age of Synapsids Read More »
The Senegal bichir represents an early branch of ray-finned fish, preserving traits that trace back nearly 380 million years.
The Senegal Bichir: A Living Fossil Read More »
The shark body plan stabilized early. By 300 million years ago, the streamlined, hydrodynamic silhouette that defines sharks today was already established.
Stem Selachians: Modern Sharks LCA Read More »
These early scales provided a vital protective layer, acting like underwater armor against predators, abrasions, and environmental threats. The keratin genes that led to scales are an interesting part of our story. When amphibians evolved onto land, scales near the tips of their evolving toes transformed into thicker protection and traction, eventually giving rise to
Keratin Genes & the Rise of Scales in Fish Read More »
The Dawn of Lungs: In the oxygen-poor waters of the Devonian period, roughly 400 million years ago, or a bit earlier. It was a significant evolutionary leap. A group known as Sarcopterygii were presentd with a formidable challenge in ancient waters that were shallow and variable. It was here that the first lungs emerged. Evolving
Lungs Evolve: Lobe-Finned Fish and the Lungfish Ancestor Read More »
By about 375 million years ago, several animal lineages had evolved long-term memory to navigate a changing world, remembering feeding sites, water access, and safe routes between land and water. This likely included vertebrates like Tiktaalik.
Long-Term Memory Evolves: Tiktaalik Read More »
Vision evolved as early as 540 million years ago during the Cambrian explosion. The ability to see, alongside the development of hearing, provided organisms with the evolutionary advantage of sensing their environment from a distance. This sensory evolution necessitated the development of larger brains for the complex processing of visual data, marking a pivotal moment
Vision Emerges: The Pre-fish Chordates Read More »
From no sentience or presentience to solidly “Simple Sentience,” early fish during this time represent our ancestral beings that started to suffer and feel the dichotomy of pleasure and pain. Haikouichthys (circa 520 Million Years Ago): Dwelling in the ancient seas of the Cambrian period, Haikouichthys is among the earliest forms of vertebrate life, showcasing fundamental advancements
Simple Sentience Settles: Haikouichthys Read More »
