Terreneuvian

The Terreneuvian is a proposed geological period within the Cambrian Period, part of the Paleozoic Era. It is one of several subdivisions that have been suggested to refine the traditional Cambrian timescale, which currently consists of three stages: the Terreneuvian, Serpukhovian, and Furongian. The name "Terreneuvian" derives from the Latin words *terra* (meaning "earth") and *neovius* (meaning "new"), reflecting its position as the earliest division of the Cambrian.

The Terreneuvian spans from the beginning of the Cambrian Period, approximately 541 million years ago, until around 524 million years ago. This interval marks the appearance of many of the first complex multicellular organisms, including early animals with hard body parts such as trilobites, sponges, and brachiopods. The period is also associated with the Cambrian Explosion, a rapid diversification of life forms that established the foundations of most modern animal phyla.

The Terreneuvian is further divided into two stages: the Fortunian and the Dapingian. The Fortunian, the earliest stage, covers the initial burst of biodiversity, while the Dapingian follows, characterized by continued evolutionary innovation. Fossil evidence from this time includes small shelly fossils, which provide critical insights into early marine ecosystems.

Geologically, the Terreneuvian corresponds to the deposition of sedimentary rocks such as the Tommotian and Atdabanian formations, which contain abundant fossil records. The period is significant for its role in shaping the evolutionary trajectory of life on Earth, making it a key focus of paleontological and stratigraphic studies. While not yet officially recognized by the International Commission on Stratigraphy, the Terreneuvian remains an important conceptual framework in geological research.