Interactions
The Rhynie chert, by preserving a snapshot of an ecosystem in situ in high fidelity, gives a unique opportunity to observe interactions between species and kingdoms. There is evidence of parasitic behaviour by fungi on algae Palaeonitella, provoking a hypertrophic response. Herbivory is also evident, judging by boring and piercing wounds in various states of repair, and the mouthparts of arthropods.
Coprolites - fossilised droppings - give a useful insight of what animals ate, even if the animals cannot be identified. Coprolites found in the Rhynie chert are typically between 0.5 and 3 mm in size, and contain a variety of contents. Analysis of coprolites allows the identification of different feeding modes, including detritovory and herbivory; some coprolites are so densely packed with spores that it is possible that these made up a substantial proportion of some organisms' diets.
Plants responded to fungal colonisation in different ways, depending on the fungus. The rhizoids of Nothia displayed three responses to fungal infestation: the hyphae of some (mutualistic) colonists were encased by plant cell walls; other (parasitic) fungi were met with typical host responses of increased rhizome cell size; while yet other fungi solicited an increase in thickness and pigmentation of cell walls. Once inside a plant cell, fungi produced spores, which are found in decaying plant cells; the cells may have decayed as a defence mechanism to prevent the fungi from spreading.
Fungal interactions are known to promote speciation in modern plants, and presumably also affected Devonian diversity by providing a selection pressure.
Mycorrhizae are also found in the Rhynie chert.
Read more about this topic: Rhynie Chert
Famous quotes containing the word interactions:
“In child rearing it would unquestionably be easier if a child were to do something because we say so. The authoritarian method does expedite things, but it does not produce independent functioning. If a child has not mastered the underlying principles of human interactions and merely conforms out of coercion or conditioning, he has no tools to use, no resources to apply in the next situation that confronts him.”
—Elaine Heffner (20th century)
“In our interactions with people, a benevolent hypocrisy is frequently required—acting as though we do not see through the motives of their actions.”
—Friedrich Nietzsche (1844–1900)
“Whereas children can learn from their interactions with their parents how to get along in one sort of social hierarchy—that of the family—it is from their interactions with peers that they can best learn how to survive among equals in a wide range of social situations.”
—Zick Rubin (20th century)