Crininicaminus giberti isp. nov.: Tubular trace fossil armored with crinoid stem plates from the Upper Permian Kamiyasse Formation, Northeastern Japan

Abstract

The tubular trace fossil Crininicaminus giberti, a horizontal tubular fossil burrow whose wall consists of numerous crinoid stem plates, occurs in the Upper Permian Kamiyasse Formation of northeastern Japan. The trace fossil described here measures 40-70 mm in length and 7-20 mm in diameter. The outer wall of the tube is characterized by numerous skeletal fragments, with most being crinoid stem plates (2 mm in diameter) and lesser fragments of brachiopods and other invertebrates. The inner wall of the tube is covered with a smooth lining devoid of crinoid skeletal elements. Because stalked crinoids mainly inhabited shallow water settings prior to the Cretaceous, it is possible that additional specimens of the ichnogenus Crininicaminus will be discovered from deposits of various ages and location