The fossils at Hungry Hollow in North Middlesex are mid-Devonian in age (between 393-382 million years), during a time known as the Age of Fishes. There was a warm shallow inland saltwater sea that covered Southern Ontario, making it the perfect environment for crinoids, trilobites, starfish, corals, and many more organisms. Part of the fossil-bearing area was exposed by geological processes and melt waters from retreating glaciers that carved out the gorge at Rock Glen Conservation Area.  Years ago, shales from the locally-exposed Arkona Formation were quarried for the production of drainage tiles and brick, resulting in the two quarries that are still present today. These quarries are called the Hungry Hollow North pit and South pit, and they expose a handful of sometimes fossiliferous rock layers from the mid-Devonian Period. Both quarries are presently owned by a brick company.  Over 150 years of fossil hunting in the Arkona area, including many visits by well-known paleontologists has made Hungry Hollow famous worldwide. American paleontologist James Hall studied many fossils from Hungry Hollow such as a common coral, Heliophyllum halli, which was named after him. Another American paleontologist, Niles Eldredge, also has a local fossilized organism named after him, a trilobite called Eldredgeops. Charles Southworth was a very well-known fossil collector that lived in the nearby town of Thedford. He collected so often at Hungry Hollow that he became an expert on fossils in the area. As such, many professional paleontologists sought his advice when visiting the quarries. Several fossils are named after him, such as Phacops iowensis southworthi, a rare trilobite species found in Hungry Hollow. Today, many fossil enthusiasts come to the Hungry Hollow quarries to dig. Two brothers from Michigan, Mike and John Topor, have visited the area over 500 times, and have found numerous holotype fossils (holotype fossils are the first of that species to be found and described). One of these holotype fossils is a pyritized polychaete worm that was subsequently named after the town of Arkona and the Topor brothers themselves, Arkonips topororum. Another amazing fossil they found is a 28-armed starfish named Arkonaster topororum. Several fossils have been named after towns in the area such as a brachiopod named after the town of Arkona, Mucrospirifier arkonensis, and the town of Thedford, Mucrospirifer thedfordensis, and even the former town of Widder has a fossilized trilobite named after it, Greenops widderensis. Latin words are often used when naming fossils. For example, Microcyclus is Latin for “small wheel”. Microcyclus is a small coral that looks like a thin round wheel or button. The brachiopod fossil Petrocrania hamiltoniae is named after a collection of rock units in southern Ontario known as the Hamilton Group, that is mid Devonian in age. There are many fossils that have been found in the area that are named after paleontologists, collectors, and local town names. It is a reflection of why Hungry Hollow is so important and known worldwide.  The rock formation at the bottom of the quarry at Hungry Hollow is the Arkona Formation. It is a bluish coloured shale that is 20 metres thick, and contains fossils such as crinoids, trilobites, brachiopods, gastropods, cephalopods, pelecypods, corals, bryozoans, phyllocarids, starfish, brittlestars, and more.  The rock formation that lies above the Arkona Formation is the Hungry Hollow Member of the Widder Formation. It is two metres thick. The lower (older) half  is called the encrinal unit, and is a grey limestone that is rich in crinoid fossils. The upper (younger) half is a soft shale that is rich in fossilized corals, bryozoans, trilobites, and crinoids. Near the base of the Hungry Hollow Member is a layer of black shale that is rich in a fossilized brachiopod species called Leiorhynchus. This black shale represents a period of time when oxygen levels were low. Above the Hungry Hollow Member is the Widder Formation, which is not exposed in the Hungry Hollow North and South pits. It is, however, exposed on the north and south banks along the Ausable River, which runs between the two quarries. The Widder Formation is exposed high on the cliffs and is approximately 14 metres thick. It is a succession of grey, calcareous shale with thin limestone layers, and contains fossilized trilobites, phyllocarids, cephalopods, pelecypods, crinoids, and gastropods.   A wide variety of microfossils can be found in the area such as fish scales, fish and sharks’ teeth, conodont and scolecodont jaw elements, ostracods, and more. Throughout the formations you can find fossils that look like gold; however, they are not. These fossils have been pyritized, which occurs in oxygen-poor environments, when bacteria breaks down the original organic material, replacing it with pyrite (FeS2). The Widder Formation contains cephalopods that are completely pyritized, making them look like a gold spear or spike. Epifauna are animals that live attached to the seafloor or on the surfaces of other aquatic organisms. The fossils of these types of animals (e.g., bryozoans) are common at Hungry Hollow. There has been much research done on the fossils and formations at Hungry Hollow. One study in particular used fossilized corals from Hungry Hollow to infer mid-Devonian climate, and the degree of current turbidity (a measure of the cloudiness of water) in the marine environment in which the coral lived. The coral’s eating habits were investigated by cutting corals from the cup to the tip. The thicknesses of the growth layers was an indicator of food availability. Interestingly, if all the lines on the exterior of the coral are present, you can count them (under a microscope) from the tip to the cup to determine its age when it died.  Much information has been collected about the paleoenvironment at Hungry Hollow just by looking at the small, conical shells of Tentaculites, found in the Arkona Formation. If all the fossils of Tentaculites are aligned (end-to-end) in the same orientation, it is a good indicator of the direction of the water current, as the force of the current would have aligned the shells in the same direction.  After