One of the earliest known true dinosaurs in the Dinosauria order is Eoraptor lunensis. From this predatory bird-like precursor, the birds and dinosaurs emerged. This direct-line ancestor evolved into theropods, birds, sauropods and ornithischians. Eoraptor emerged during the Late Triassic period, approximately 231.4 million years ago, in what is now Argentina. It is considered one […]
First True Dinosaur: Eoraptor lunensis. Read More »
In more advanced forms, play becomes a complex tool for social bonding, emotional learning, and cognitive development. Carnivores like wolves and cats engage in cooperative games that refine group hunting skills, while elephants are known for their intricate, playful interactions that build emotional connections. Among primates, play takes on its most elaborate forms, fostering problem-solving,
Higher Play Evolves in Social Mammals Read More »
Play in its most basic form likely began as simple, physical interactions aimed at honing survival skills. Modern animals like squirrels, kangaroos, and hedgehogs still exhibit these foundational behaviors, engaging in chasing, pouncing, and wrestling. These actions help young animals develop coordination and reflexes while providing a safe way to practice life-essential tasks. Surprisingly, even
Early Play Evolves in Mammals Read More »
Around 25 to 29 million years ago, Old World monkeys, including species like baboons and macaques, branched off from the common ancestor shared with apes. Unlike their ape cousins, Old World monkeys retained their tails and adapted to a wider range of habitats, from forests to savannas. Baboons, known for their ground-dwelling behavior, exhibit strong
Baboons Branch Off: Old World Monkeys Read More »
The last surviving primate before the great apes! Gibbons are a “lesser ape” that branched off from our common ancestor with great apes. By this time, our ancestors had already lost their tails (like all apes) and were very agile in trees, using brachiation (arm-swinging) to move through the canopy. Gibbons are known for their
Gibbons Branch Off: Genus Hylobates Read More »
Around 240 million years ago, during the late Triassic period, a crucial evolutionary development unfolded within the lineage that would give rise to mammals. It is believed that the XX/XY sex-determination system emerged in a common ancestor of mammals, possibly within the genus Therapsida, a group of synapsids that exhibited both reptilian and mammalian traits.
XX/XY Sex System Emerges: A Tale of Mammalian Evolution Read More »
The movement of fluids, or circulation, evolved around 3.5 billion years ago in single-celled organisms to distribute nutrients and remove waste. Blood, a specialized fluid carrying nutrients and waste, evolved much later, around 1.2 billion years ago in multicellular organisms. It evolved to feed internal cells and carry away waste. As oxygen levels rose and
By about 125 million years ago, mammals likely increased their vocabulary above a dozen and perhaps for some species at times into the hundreds. This vocabulary, or signaling, was a series of gestures, grunts, and screeches. Today, mammals from this lineage communicate with a range of signals and gestures, not unlike our abstract vocabulary. We
Animal Vocabulary: Dozens of Words Read More »
In a testament to our understanding of evolution, archosaurs emerged around 255 million years ago, eventually giving rise to dinosaurs about 230 million years ago. Bridging this gap, the dinosauromorphs – a transitional group between archosaurs and dinosaurs – evolved approximately 245 million years ago. One notable early dinosauromorph is Asilisaurus kongwe, found in present-day
Dinosauromorphs Emerge: Asilisaurus kongwe Read More »
The earliest known dinosaur is Nyasasaurus parringtoni, which lived during the Middle Triassic period, around 243 million years ago. Discovered in Tanzania, Nyasasaurus represents a key transitional form, showcasing features that are both dinosaurian and pre-dinosaurian, highlighting the evolutionary path leading to more well-known dinosaurs of the Late Triassic and beyond. This discovery pushes back
Nyasasaurus parringtoni Read More »
Before dinosauromorphs like Asilisaurus, the evolutionary lineage would include earlier archosaurs. One such early archosaur is Marasuchus lilloensis, which lived around 240 million years ago. Marasuchus exhibits several primitive features that are on the evolutionary path towards dinosaurs. Kingdom: Animalia > Phylum: Chordata > Class: Reptilia > Order: Dinosauriformes 30 to 40 cm (12 to
Marasuchus lilloensis Read More »
Around 60 million years ago, the early ancestors of primates began to develop a crucial adaptation: the opposable thumb. This evolutionary milestone marked the beginning of increased dexterity and the ability to grasp objects more effectively. Living in the dense canopies of prehistoric forests, these early primates used their newly opposable thumbs to navigate their
Opposable Thumb Emerges Read More »
Likely between 25 and 30 million years ago, the evolution of the apes brought about further refinement of the opposable thumb. This period saw the divergence of the lineages that would lead to modern “lesser” apes like gibbons as well as later “great” apes, including orangutans, gorillas, and chimpanzees. The ape thumb evolved to become
Protozoa emerge from a branch of eukaryotes and both branches survive today. Domain: Eukaryota > Kingdom: Protista
Orangutans (genus Pongo) are great apes native to Indonesia and Malaysia, characterized by their distinctive reddish-brown fur, long arms, and intelligent behavior. They are the most arboreal of all great apes, spending most of their time in trees, and are skilled climbers and swing between branches with ease. Orangutans are also known for their advanced
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 »
Long-Term Memory: By about 375 million years ago, the foundations for long-term memory were likely established among the more complex vertebrates, facilitating survival in increasingly varied and challenging environments. Tiktaalik is a prime example of this evolutionary milestone. It is an extraordinary creature that bridged the gap between aquatic fish and amphibians. With its forward-facing
Long-Term Memory Evolves: Tiktaalik Read More »
Chemoreception, the ability to detect chemical stimuli, likely emerged around 600 million years ago among some of the earliest soft-bodied multicellular organisms. This evolutionary leap did not necessarily require a proto- or pre-brain in the complex sense associated with later animals but rather relied on cellular mechanisms capable of processing chemical information. These early forms
Chemoreception: Taste and Smell Emerge Read More »
Long before the complexity of full-fledged nervous systems, elaborate senses, and brains, life on Earth developed the basic ability to perceive and react to mechanical stimuli—a process known as cellular mechanosensitivity. Domain: Eukaryota > Kingdom: Animalia > Phylum: Porifera (sponges)
Touch Emerges: Proto-Sensing. Read More »
