Porpoises are small dolphin-like cetaceans classified under the family Phocoenidae. Although similar in appearance to dolphins, they are more closely related to narwhals and belugas than to the true dolphins. There are eight extant species of porpoise, all among the smallest of the toothed whales. Porpoises are distinguished from dolphins by their flattened, spade-shaped teeth distinct from the conical teeth of dolphins, and lack of a pronounced beak, although some dolphins also lack a pronounced beak. Porpoises, and other cetaceans, belong to the clade Cetartiodactyla with even-toed ungulates.
William Healey Dall was an American naturalist, a prominent malacologist, and one of the earliest scientific explorers of interior Alaska. He described many mollusks of the Pacific Northwest of North America, and was for many years America's preeminent authority on living and fossil mollusks.
Ecphora gardnerae is a species of extinct predatory ocenebrinid murex gastropod. Shells of E. gardnerae are found in Miocene-aged marine strata of Maryland and Virginia.
Nuculanidae is a family of small saltwater clams, marine bivalve molluscs in the order Nuculanida. Species in this family are found in all seas, from shallow to deep water.
Hystrivasum horridum, common name the rough or shaggy vase, is a fossil species of medium-sized predatory gastropod in the family Turbinellidae. This species is extinct and is found in the Pleistocene deposits of Florida.
The Arcadia Formation is an Early Miocene geologic formation in Florida, United States. It is part of the Hawthorn Group.
Cryptogemma is a genus of sea snails, marine gastropod mollusks in the family Turridae, the turrids.
Xanthodaphne is a genus of sea snails, marine gastropod mollusks in the family Raphitomidae.
Hindsiclava is a genus of sea snails, marine gastropod mollusks in the family Pseudomelatomidae,
Aforia is a genus of sea snails, marine gastropod mollusks in the family Cochlespiridae.
Antiplanes is a genus of sea snails, marine gastropod mollusks in the family Pseudomelatomidae,.
Cochlespira is a genus of sea snails, marine gastropod mollusks in the family Cochlespiridae.
Ithycythara is a genus of small sea snails, marine gastropod mollusks in the family Mangeliidae.
Zonaria is a genus of sea snails, marine gastropod molluscs in the subfamily Zonariinae of the family Cypraeidae, the cowries.
Microstelma is a genus of minute sea snails, marine gastropod mollusks or micromollusks in the family Zebinidae.
Crassispira perrugata is an extinct species of sea snail, a marine gastropod mollusk in the family Pseudomelatomidae, the turrids and allies.
Hindsiclava eupora is an extinct species of sea snail, a marine gastropod mollusc in the family Pseudomelatomidae, the turrids and allies.
Hindsiclava perspirata is an extinct species of sea snail, a marine gastropod mollusc in the family Pseudomelatomidae, the turrids and allies.
Monilispira bigemma is an extinct species of sea snail, a marine gastropod mollusc in the family Pseudomelatomidae.
Orthaulax is an extinct genus of sea snails in the family Strombidae.
