Cryptospore

Cryptospores are fossilised primitive plant spores that first appear in the fossil record during the middle of the Ordovician period.

Evidence that cryptospores derive from land plants

Occurrence

Cryptospores are generally found in non-marine rocks and decrease in abundance with distance offshore. This suggests that any cryptospores found in the marine environment were transported there by the wind from the land, rather than originating from the marine environment.

Wall Ultrastructure

The walls of cryptospores consist of many lamellae (thin sheets). Liverworts, thought to be the most primitive land plants, also have this spore wall morphology.

Chemical composition

(Some) cryptospores are composed of sporopollenin and have the same chemical makeup as co-occurring trilete spores.[1]

Other information

Recently, fossils of plant sporangia have been found in Oman with cryptospores showing concentric lamellae in their walls, similar to liverworts. The earliest known cryptospores are from Middle Ordovician (Dapingian) strata of Argentina.[2] Spores from the Lindegård Mudstone (late Katian–early Hirnantian) represent the earliest record of early land plant spores from Sweden and possibly also from Baltica and implies that land plants had migrated to the palaeocontinent Baltica by at least the Late Ordovician.[3] This discovery reinforces the earlier suggestion that the migration of land plants from northern Gondwana to Baltica in the Late Ordovician was facilitated by the northward migration of Avalonia,[4] which is evidenced by the co-occurrence of reworked, Early–Middle Ordovician acritarchs, possibly suggesting an Avalonian provenance in a foreland basin system.

gollark: It could record locally and upload later, though.
gollark: This person apparently reverse-engineered it statically, not at runtime, but it *can* probably detect if you're trying to reverse-engineer it a bit while running.
gollark: > > App behavior changes slightly if they know you're trying to figure out what they're doing> this sentence makes no sense to me, "if they know"? he's dissecting the code as per his own statement, thus looking at rows of text in various format. the app isn't running - so how can it change? does the app have self-awareness? this sounds like something out of a bad sci-fi movie from the 90's.It's totally possible for applications to detect and resist being debugged a bit.
gollark: > this is standard programming dogma, detailed logging takes a lot of space and typically you enable logging on the fly on clients to catch errors. this is literally cookie cutter "how to build apps 101", and not scary. or, phrased differently, is it scary if all of that logging was always on? obviously not as it's agreed upon and detailed in TikTok's privacy policy (really), so why is it scary that there's an on and off switch?This is them saying that remotely configurable logging is fine and normal; I don't think them being able to arbitrarily gather more data is good.
gollark: > on the topic of setting up a proxy server - it's a very standard practice to transcode and buffer media via a server, they have simply reversed the roles here by having server and client on the client, which makes sense as transcoding is very intensive CPU-wise, which means they have distributed that power requirement to the end user's devices instead of having to have servers capable of transcoding millions of videos.Transcoding media locally is not the same as having some sort of locally running *server* to do it.

See also

Paleobotany Palynology Spore Land plants Strother, P. Wellman, C. Steemans, P. Rubinstein, C.V.


References
  1. Steemans, P.; Lepot, K.; Marshall, C.P.; Le Hérissé, A. and Javaux, E.J. (2010). "FTIR characterisation of the chemical composition of Silurian miospores (cryptospores and trilete spores) from Gotland, Sweden" (PDF). Review of Palaeobotany and Palynology. 162 (4): 577–590. doi:10.1016/j.revpalbo.2010.07.006.CS1 maint: multiple names: authors list (link)
  2. Rubinstein, C.V.; Gerrienne, P.; de la Puente, G.S.; Astini, R.A.; Steemans, P. (2010). "Early Middle Ordovician evidence for land plants in Argentina (eastern Gondwana)". New Phytologist. 188 (2): 365–369. doi:10.1111/j.1469-8137.2010.03433.x. PMID 20731783. S2CID 24070744.
  3. Badawy, A.S.; Mehlqvist, K.; Vajda, V.; Ahlberg, P. and Calner, M. (2014). "Late Ordovician (Katian) spores in Sweden: oldest land plant remains from Baltica". GFF. 136 (1): 16–21. doi:10.1080/11035897.2014.899266.CS1 maint: multiple names: authors list (link)
  4. Steemans, P.; Wellman, C.H. and Gerrienne, P. (2010). "Paleogeographic and paleoclimatic considerations based on Ordovician to Lochkovian vegetation". Geological Society, London, Special Publications. 339 (1): 49–58. doi:10.1144/SP339.5.CS1 maint: multiple names: authors list (link)
  • Edwards, D., Morris, J. L., Richardson, J. B., & Kenrick, P. (2014). Cryptospores and cryptophytes reveal hidden diversity in early land floras. New Phytologist 202(1), 50-78, .
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