Bernhard Lundgren`s (1891) description of Ophiomorpha

The original description of the ichnogenus Ophiomorpha Lundgren, 1891 was published in Swedish. An English translation is provided to make Lundgren's comments available to a larger audience. Lundgren's description deals with two forms of Ophiomorpha nodosa in loose rocks from southern Sweden. The first form consists of cylindrical to slightly conical objects with knobby surfaces. They are straight or slightly curved, and some are compressed. Diameters are 18–30 mm, and lengths 30–110 mm. The specimens appear to be fragments of longer objects consisting of ferruginous claystone. The few scraps of surrounding rock adhering to their surfaces suggest derivation from beds of ferruginous claystone or sandstone. The second form consists of external molds, but a few specimens have a piece of nearly smooth core preserved. Between the core and the mold is a space as much as 2 mm wide. The impression (mold) is dimpled by pits 2–5 mm deep and typically wider than high. Maximum and minimum diameters of the molds vary from 16×7 mm to 28 × 17 mm, while maximum preserved length is 25 cm. This form of Ophiomorpha is straight to slightly curved and one specimen is branching. No bedrock sources are known for these two forms of Ophiomorpha, but the first may be Tertiary. Reference: B. Lundgren, 1891: Studier öfver fossilförande lösa block. Geologiska Föreningens i Stockholm Förhandlingar, 13(2), pp. 111–121.