Discussion Overview
The discussion revolves around the identification of fossils collected from the lower Jurassic (Toarcium or Lias epsilon) in Holzmaden, Germany. Participants explore various hypotheses regarding the nature of the fossils, which are described as thick "leaves" connected to a spherical stem, with a focus on their potential classification as either plant or marine fossils.
Discussion Character
- Exploratory
- Debate/contested
- Technical explanation
Main Points Raised
- One participant suggests the fossils resemble ginkgo leaves, although they question their presence in a marine environment.
- Another participant proposes that the fossils could be typical brachiopods from that era, sharing personal experiences of similar finds in New Zealand.
- A participant expresses doubt about the ginkgo identification, noting the rarity of land plant leaves in marine environments and considers the possibility of crinoids instead.
- Concerns are raised about the interpretation of the "stem," with one participant asserting that the main object is likely a brachiopod, which can exhibit distorted shapes due to burial pressure.
- Another participant mentions their abundance of crinoid fossils and questions the identification of the "leaves," clarifying that crinoids are not plants.
- One participant identifies the fossils as potentially being nummulites, a type of foraminiferan, but acknowledges that these are typically found in later geological periods.
- Another participant confirms that nummulites are first found in upper Cretaceous rocks, reiterating the lower Jurassic origin of the discussed fossils.
- A suggestion is made to consult local university paleontology departments for further identification assistance.
- One participant proposes that the fossils might not be fossils at all but rather a pyrite sun, an inorganic formation.
- Another participant shares a picture of a real fossil from the same location, enhancing the discussion with visual context.
Areas of Agreement / Disagreement
Participants express multiple competing views regarding the identification of the fossils, with no consensus reached on their classification. Various hypotheses are presented, including brachiopods, crinoids, and inorganic pyrite formations.
Contextual Notes
Participants note the limitations of identifying fossils based solely on pictures, and some express a lack of access to fossil reference materials, which may affect their conclusions.
