Turrid

These are sea snails called turrids.

They live in every ocean. Some live in warm water. Others live in very cold water. They can live in shallow seas or deep down. Some live far below the waves.

These snails are hunters. They use a poison gland to catch food. They mostly eat small worms.

Most turrid shells are small. Some are less than one inch long. Their shells have many shapes. Some have a little notch on the edge.

Scientists study these snails. They found that these snails belong to many groups. It is a big family of life.

Turrids are a large group of predatory sea snails.

These snails live in every ocean. They live in warm and cold waters. Some stay near the shore. Others live in very deep water. Some live more than 8,000 meters down. Most live in the neritic zone, which is the part of the sea near the coast.

Turrids are hunters. They use a poison gland to catch prey. They mostly eat worms. They use a radula, which is a part with tiny teeth, to help them eat. Some turrids have lost this part.

Most turrid shells are quite small. Many are under 2 cm tall. Some adult shells reach 11.4 cm. The shells come in many shapes. Many have a V-shaped notch. This is called a turrid notch.

Scientists used to think all turrids were one big family. They found this was not true. In 2011, experts split them into 13 different families. This is because the group was polyphyletic. This means the snails did not all come from one single ancestor. Studying them is hard because many are very rare.

Turrids are a huge group of predatory sea snails. They are marine gastropod mollusks that live in every ocean on Earth. You can find them in warm tropical waters and cold polar seas. Some live near the shore in low areas. Others live in the deep, dark ocean. Some have even been found more than 8,000 meters down in the Bougainville Trench.

These snails are hunters that use special tools to eat. Most species have a poison gland to help them catch prey. They use this to hunt animals like polychaete worms. They also use it for self-defense. To eat, they use a toxoglossan radula. A radula is a part with tiny teeth. In many turrids, the radula has only two or three teeth in a row. These teeth grow from a flat plate by getting thicker at the edges.

Scientists have worked hard to name and group these snails. For a long time, people thought they all belonged to one big family called Turridae. This family was once the largest group of marine gastropods. It contained more than 4,000 species and 27,000 scientific names. However, researchers later found the group was polyphyletic. This means the snails in the group did not all come from one single ancestor.

In 2011, experts changed how we classify these snails. Scientists Bouchet, Kantor, Sysoev, and Puillandre published a new system. They split the old Turridae family into 13 separate families. These new families include names like Conorbidae, Borsoniidae, and Mangeliidae. They used anatomy and molecular phylogeny to make these choices. Molecular phylogeny is a way to study how living things are related using their DNA.

Looking at a turrid shell can tell you a lot about it. Most shells are small, often under 2 cm tall. Some adult shells can grow up to 11.4 cm. The shells have a shape called fusiform, which means they look like a spindle. Many shells have a V-shaped notch called a turrid notch. This notch sits on the upper end of the outer lip. Scientists use the notch and the shell's patterns to help group them.

Turrids are a diverse group of predatory sea snails. They are marine gastropod mollusks that live in oceans across the entire world. These animals inhabit every sea, from the cold poles to the warm tropics. They live in many different environments, from shallow coastal zones to the deep ocean. Some species have been found at depths exceeding 8,000 meters. For example, *Xanthodaphne levis* was collected in the Bougainville Trench at depths between 7,974 and 8,006 meters. While they live everywhere, most species prefer the neritic zone, which is the relatively shallow part of the ocean.

These snails are active carnivores that use specialized tools to hunt. Most species possess a poison gland to help them catch prey or defend themselves. They use this gland alongside a toxoglossan radula to hunt animals. Their prey often includes invertebrates, such as polychaete worms, but they can also prey on vertebrates. The radula is a structure used for feeding. In many turrids, the radula has only two or three teeth in a row. These teeth lack lateral teeth. The marginal teeth are of the duplex or wishbone type. These teeth do not come from two separate pieces. Instead, they grow from a flat plate. They form by thickening at the edges and elevating the rear edge from the membrane. Some turrids have actually lost both the poison gland and the radula.

Looking at a shell can reveal many details about a turrid. Most of these shells are quite small, often under 2 cm in height. However, adult shells can vary in size from 0.3 cm to 11.4 cm. The shells generally have a fusiform shape, which means they are spindle-shaped. The whorls of the shell can be broadly conical or elongate. The surface sculpture on the shells is very diverse. Some shells have axial sculpture or spiral sculpture. Others may be beaded, nodulose, striate, or reticulate. A very important feature is the aperture, which is the shell opening. The aperture often has a V-shaped indentation called a sinus or notch. This is located on the upper end of the outer lip. It is commonly called the "turrid notch." This notch accommodates the anal siphonal notch. Scientists have traditionally used the position of this notch and the shell's sculpture to classify them.

For a long time, scientists grouped these snails into one massive family called Turridae. This was once the largest family of mollusks and the largest group of marine caenogastropods. The original family contained more than 4,000 species. There were approximately 27,000 described scientific names, including both accepted names and synonyms. In some parts of the world, turrids made up more than half of all predatory gastropod species. However, researchers discovered that this large family was polyphyletic. This means the members of the group did not all share a single common ancestor. Because of this discovery, the way we classify them had to change completely.

In 2011, a major change occurred in turrid taxonomy. Researchers Bouchet, Kantor, Sysoev, and Puillandre published a new classification for the Conoidea group. They moved away from the old system to create a more accurate one. This new system was based on anatomical characters and molecular phylogeny. Molecular phylogeny is the study of evolutionary relationships using DNA. This work resolved the polyphyletic Turridae into 13 distinct monophyletic families. These families include Conorbidae, Borsoniidae, Clathurellidae, Mitromorphidae, Mangeliidae, Raphitomidae, Cochlespiridae, Drilliidae, Pseudomelatomidae, Clavatulidae, Horaiclavidae, Turridae s.s., and Strictispiridae. This new classification includes 358 currently recognized genera and subgenera.

Studying turrids has historically been a difficult task for malacologists. One reason is the massive number of taxa described at levels above the species level. The high level of species diversity also makes identification complicated. Additionally, while some species are common, many others are quite rare. Some species are known to science from only a single specimen. This rarity makes it hard to gather enough data for study. One of the most important collections of these snails is in the Academy of Natural Sciences of Philadelphia. This collection is so complete because of the specialized work of Virginia Orr Maes. She was an American malacologist who lived from 1920 to 1986.

Understanding turrids helps us understand the complex systems of marine life. They represent a huge portion of the predatory snails in our oceans. Their evolution of specialized hunting tools, like the poison gland and unique radula, shows how marine life adapts to survive. By studying their DNA through molecular phylogeny, scientists can better map the history of life in the sea. The transition from one large, incorrect family to 13 correct families shows how science constantly improves. As we find more species in deep trenches or rare habitats, our map of the ocean's biodiversity grows more detailed.