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”
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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”
Tentaculitids
Tentaculitids were Lophophorates, like Brachiopods, Bivalves, Hyolithids, Bryozoans, and Phoronids (2). This meant that they filtered plankton with a lophophore, a looping, many tentacled cephalic organ. Tentaculitids lived from the middle Cambrian to the Late Jurassic, in the past being associated with annelid worms, but being ascribed to the Lophophorates due to their shell microstructureContinue reading “Tentaculitids”
Crinoids
Crinoids were enormously successful Echinoderms that lived all over the world, starting in the Cambrian and living on today with roughly 80 species (1). Their columnals, sections of their stems, preserve especially well as fossils, and their filter feeding habits enabled them to thrive in a plethora of marine environments. Crinoids found at Seven StarsContinue reading “Crinoids”
Conodonts
Conodonts are perhaps the most important fossils to our daily life because of their use as index fossils. Their “teeth,” called conodont elements, preserve well and can be found in almost any Paleozoic sedimentary rock. While traditionally seen as vertebrates, even fish, their taxonomic positions are still disputed (4). Conodonts found at Seven Stars ConodontaContinue reading “Conodonts”
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”
Old Bringing Fossils to Life
This site has gone through numerous changes since its release in July, 2021! The information in this branch of the site may not be as up to date as the newer parts. If a post has outdated or incorrect information, a small icon can be found in the corner of its cover picture, alerting youContinue reading “Old Bringing Fossils to Life”
Gastropods
Like most mollusks, gastropods have a toothed tongue-like organ called the radula for food processing. Gastropods are the most successful mollusks today, with over 40,000 species. They inhabit saltwater, freshwater, and many biomes on land, and are usually characterized by a large muscular foot and an offset-spiraling shell (2). Gastropods found at Seven Stars BembexiaContinue reading “Gastropods”