Seven Stars was home to a stunning, diverse ecosystem that sustained a vast array of organisms. It was only able to do so because of a complex chain of geological events that set up the area for the life documented here. The Seven Stars ecosystem was heavily influenced by the step-by-step formation of the modernContinue reading “Geological Background of Seven Stars”
Tag Archives: Devonian
Polychaetes
Polychaetes, segmented worms bearing parapodia, are first found in the Cambrian Period, and all exhibit an elongated body broken into many segments. More specifically, the Polychaete worms within the order Eunicida are also first found in the Cambrian and are further characterized by ventral maxillae and dorsal mandibles positioned within the pharynx. Eunicids are foundContinue reading “Polychaetes”
Anthozoans
Anthozoans, or corals, are a diverse group of cnidarians that build complex living structures out of calcium. They are incredibly successful, having about 1500 living species today. Each individual coral animal is called a polyp; these can be either colonial or solitary. They filter feed with numerous stinging tentacles and represent one of the mostContinue reading “Anthozoans”
Monoplacophora
Monoplacophora is a little known molluscan group that is represented by one species at Seven Stars. They have traditionally been viewed as the original stem mollusk, as they are among the first undoubted mollusk fossils to be found in the Cambrian. They are still alive today, but unlike many fossil forms, inhabit deeper waters thatContinue reading “Monoplacophora”
Hyolitha
Hyolithids were organisms with conical shells with a triangular cross section that have been attributed to Annelid worms, Mollusks, and even a new phylum. More recently they have been confirmed to have been lophophorates and their mode of life uncovered. Hyoliths ranged from the Cambrian to the Permian, but were rare in the late Paleozoic.Continue reading “Hyolitha”
Cephalopods
Cephalopods were mollusks, like gastropods, scaphopods, chitons, and bivalves. Like many mollusks they had shells made of calcium carbonate and processed food with a toothed, tongue-like radula. Cephalopods are still alive today, and include the nautilus, squid, cuttlefish, octopuses, and others. Cephalopods found at Seven Stars Agoniatites vanuxemi VERY RARE Bactrites aciculum UNCOMMON Michelinoceras telamonContinue reading “Cephalopods”
Trilobites
Trilobites were enormously successful arthropods that lived throughout the Paleozoic (2). They are thought to have been most closely related to living horseshoe crabs, but are themselves not chelicerates (3). Four species of trilobites have been found at Seven Stars, but as usual only their hard exoskeletons are preserved. Trilobites found at Seven Stars DipleuraContinue reading “Trilobites”