Science Daily - Fossils

Modern HIV medicine is based on a common genetic mutation. Now, researchers have traced where and when the mutation arose -- and how it protected our ancestors from ancient diseases.

The Arctic landscape during the Cretaceous Period may have been dominated by the dinosaurs, but the rivers and streams held something more familiar. Alaska's fresh waters 73 million years ago were teeming with the ancient relatives of today's salmon, pike and other northern fish. A new article has named three new species of fish from that time period, including a salmonid, dubbed Sivulliusalmo alaskensis.

Newly discovered species of extinct fish shows striking similarities to unrelated modern-day predators, suggesting certain traits have emerged multiple times and remained consistent over hundreds of millions of years.

Life depends on genes being switched on and off at exactly the right time. Even the simplest living organisms do this, but usually over short distances across the DNA sequence, with the on/off switch typically right next to a gene. This basic form of genomic regulation is probably as old as life on Earth. A new study finds that the ability to control genes from far away, over many tens of thousands of DNA letters, evolved between 650 and 700 million years ago. It probably appeared at the very dawn of animal evolution, around 150 million years earlier than previously thought. The critical innovation likely originated in a sea creature, the common ancestor or all extant animals.

Tyrannosaurus rex evolved in North America, but its direct ancestor came from Asia, crossing a land bridge connecting the continents more than 70 million years ago, according to a new study.

A new study is reshaping how scientists date dinosaur fossils in Alberta's Dinosaur Provincial Park (DPP). Using advanced drone-assisted 3D mapping, researchers have uncovered significant variations in a key geological marker, challenging long-standing methods of determining the ages of dinosaur fossils.

At a conference in Washington D.C. in 2000, the secretoglobin super family of proteins was named to classify proteins with structural similarities to its founding member uteroglobin. Now, 25 years later, there is still little known about the basic functions of these proteins, prompting a group of researchers to dive into their evolutionary origins. This bioinformatic survey reported that secretoglobins, or SCGBs -- originally thought to be exclusive to mammals -- are also found in turtles, crocodilians, lizards, and birds. These new findings suggest that these proteins evolved earlier than dinosaurs and share a basic function that is not yet discovered.

Why do some ancient animals become fossils while others disappear without a trace? A new study reveals that part of the answer lies in the body itself. The research shows that an animal's size and chemical makeup can play an important role in determining whether it's preserved for millions of years -- or lost to time.

The very first cells obtained their energy from geochemical reactions. Researchers have now managed to recreate this ancient metabolic process in their laboratory.

Imagine a crocodile built like a greyhound -- that's a sebecid. Standing tall, with some species reaching 20 feet in length, they dominated South American landscapes after the extinction of dinosaurs until about 11 million years ago. Or at least, that's what paleontologists thought. A new study shows the Caribbean Islands were a refuge for the last sebecid populations at least 5 million years after they went extinct everywhere else.

Even under today's climatic conditions, the long-extinct straight-tusked elephant could still live in Europe. This is the conclusion of a recent study. For this finding, the research group combined fossil finds with reconstructions of past climates.

New research questions the evolutionary history of some of our most peculiar mammals.

A 113-million-year-old hell ant that once lived in northeastern Brazil is now the oldest ant specimen known to science, finds a new report. The hell ant, which was preserved in limestone, is a member of Haidomyrmecinae -- an extinct subfamily that only lived during the Cretaceous period. These ants had highly specialized, scythe-like jaws that they likely used to pin or impale prey.

Ancient DNA analysis challenges our understanding of the ancient Phoenician-Punic civilization. An international team of researchers analyzing genome-wide data from 210 ancient individuals has found that Levantine Phoenician towns contributed little genetically to Punic populations in the central and western Mediterranean despite their deep cultural, economic, and linguistic connections.

What roils beneath the Earth's surface may feel a world away, but the activity can help forge land masses that dictate ocean circulation, climate patterns, and even animal activity and evolution. In fact, scientists believe that a plume of hot rocks that burst from the Earth's mantle millions of years ago could be an important part in the story of human evolution.

Researchers examined teeth and skulls of 99 extinct crocodylomorph species and 20 living crocodylian species to reconstruct their dietary ecology and identify characteristics that helped some groups persist through two mass extinctions. They discovered that one secret tocrocodylian longevity is their remarkably flexible lifestyles, both in what they eat and the habitat in which they get it.

Rhinos that flourished across much of North America 12 million years ago gathered in huge herds, according to a new study.

Evidence shows that hunter-gatherers were crossing at least 100 kilometers (km) of open water to reach the Mediterranean island of Malta 8,500 years ago, a thousand years before the arrival of the first farmers.

A new genomic study has uncovered long-lost genetic diversity in mammoth lineages spanning over a million years, providing new insights into the evolutionary history of these animals.

Researchers formally describe Helmetia expansa, offering new insights into its anatomy, behavior and evolutionary relationships.