Latest posts tagged with #Rusophycus on Bluesky
An ichnofossil: Ordovician trilobite trackways, preserved as locomotion traces on the ancient sea floor.
Unlike body fossils, these are trace fossils recording behavior rather than anatomy.
#ichnofossil #Rusophycus #trilobite #ichnology #fossils #geology
Black & white image of an irregularly ovoid trace fossil aggregation in plan view, standing in high positive relief on the underside of a siltstone bedding surface. The mound-like structure has a central depression, surrounded by many coalescing bilobate (bean-shaped) projections with transverse striations ("scratch marks") marking individual excavations of the trilobite feeding/resting trace known as Rusophycus. The traces have been coated in a fine white sublimate of ammonium chloride to highlight fine details. In the background, the underside of the bedding surface bears numerous small "tool marks" also in positive relief. Scale bar in lower right = 2 cm. Unique specimen in the Invertebrate Paleontology collections of the Royal Ontario Museum. Collected & donated by M. Farivar.
Close-up view of the upper centre portion of the first photo, showing two bulges along the margin that are lateral views of a pair of slightly overlapping Rusophycus excavations. On the right side, a single more or less discrete Rusophycus is seen in plan view. Numerous paired sets of scratches mark shorter segments of linear trails. Scale bar = 2 cm.
Side view of trace fossil slab in correct orientation, with mound-shaped Rusophycus aggregation projecting down from lower bed surface. Cross section of siltstone bed shows an upper surface with a central ripple crest flanked by a trough on each side. Scale bar = 5 cm.
Cartoon interpretation of possible sequence of formation of the trace aggregation, showing multiple Flexicalymene individuals excavating hypothetical food source. All illustrations from Brandt & Rudkin 2011, Ichnos 18:35-40.
A #TrilobiteTuesday #trace #fossil! Unusual occurrence of #Rusophycus, w multiple overlapping bilobate traces forming a bowl-shaped aggregation on underside of bed. Probably excavated by several #Flexicalymene individuals exploiting an unknown food source. Late #Ordovician (~445 MYA) #Ontario 🇨🇦
