Devonian Fossil Shark Bundle Scottish Acanthodians

Devonian Fossil Shark Bundle: Cheiracanthus murchisoni, Diplacanthus crassisimus & Mesacanthus pusillus

 500,00

Super Value Shark fossil bundle.

Get these stunning three Spiny Sharks: Mesacanthus, Cheiracanthus and Diplacanthus for one great price.

The Cheiracanthus and Diplacanthus from head to tip of the tail are 7 cm/2,7 inch long while the Mesacanthus is 4 cm/ 1,57 inch.

1 in stock

Description

About Diplacanthus crassisimus, Cheiracanthus murchisoni & Mesacanthus pussillus Devonian Fossil Shark Bundle

Physical Description

Mesacanthus pusillus is a small fish with spines located on the leading edge of all of its fins, with exception of the tail. It has a single dorsal fin, an anal fin, and pectoral and pelvic fins, and located between the latter two it has a pre-pelvic fin. The name Mesacanthus derives from the spine of the pre-pelvic fin, meaning “middle spine”. These spines served as a deterrent against larger predatory fishes.

Diplacanthus crassisimus is also an acanthodian. It is a small fish ranging from 10 mm to about 150 mm. D. crassisimus is characterized by particularly long dorsal fin spines. The spines on its pectoral, pelvic, prepelvic, and anal fins were smaller but nevertheless large when compared to most other acanthodians.

Cheiracanthus murchisoni is the largest of the acanthodians from the Orcandian basin. Its a large fish ranging from 60 mm to about 250 mm. C. murchisoni on first impression looks like a very large Mesacanthus. Like its smaller cousin it had only one dorsal fin spine. But it differs as this spine was more to the middle of the body compared dorsal fin of the Mesacanthus which is situated more to the rear of the fish. The name Cheiracanthus comes from greek, meaning hand spine (cheira-canthus)

Age and Distribution

These acanthodians are from the Middle Devonian of Scotland. This fish lived approximately 385 million years ago. At the time this area of Scotland was part of the Orcadian Basin, which was a huge complex of lakes that stretched for hundreds of miles. During this period plants started to rapidly colonize the land and fishes dominated nearly every niche of seas and lakes, hence why this period is also known as the “Age of Fishes”. These acanthodians co-inhabited the lake with other fishes like the osteolepids Gyroptychius, Osteolepis, and Thursius, the porolepid Glyptolepis, the lungfish Dipterus, the enigmatic Palaeospondylus gunni and the placoderms Dickosteus, Coccosteus, Pterichtyodes, Rhamphodopsis and Homostius.

About the Acanthodii Devonian Fossil Shark Bundle

Evolutionary Significance

The Acanthodii are among the earliest jawed vertebrates known in the fossil record. The oldest acanthodians found are from the Lower-Silurian. This group disappears from the known fossil record at the Permian-Triassic extinction event, long after they had already dwindled in diversity.

Taxonomy

Diplacanthus crassisimus belongs to the Diplacanthidae which is a subclass of the Acanthodii (‘spiny sharks’, which means that, though they also had a skin cover of denticles, it is uncertain that they are closely related to sharks). Other Diplacanthidae from Middle-Devonian of Scotland are: Diplacanthus tenuistriatus and Rhadinacanthus longispinus.

Mesacanthus pusillus belongs to the Mesacanthidae which is another subclass of the Acanthodii. There are no other known Mesacanthidae from Middle Devonian Scotland, but the genus is represented in the Lower Devonian of Scotland.

Cheiracanthus murchisoni belongs to the Cheiracanthidae which is a subclass of the Acanthodii. Other Cheiracanthidae from Middle-Devonian of Scotland are: Cheiracanthus latus.

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