tag:blogger.com,1999:blog-5517176012861550589.post2125844659097912277..comments2023-06-14T21:50:15.221+10:00Comments on Ediacaran: Squid Wannabes in the CambrianChris Nedinhttp://www.blogger.com/profile/06978886926715669724noreply@blogger.comBlogger7125tag:blogger.com,1999:blog-5517176012861550589.post-58583883240189596472011-03-19T10:43:58.493+11:002011-03-19T10:43:58.493+11:00thanks for the quick reply! =)
but things like tha...thanks for the quick reply! =)<br />but things like that happen time to time, right? hallucigenia once walked on the spikes and stuff... i would really like to know what nectocaris was though...Petrhttps://www.blogger.com/profile/06537642993606964893noreply@blogger.comtag:blogger.com,1999:blog-5517176012861550589.post-87441907649301868852011-03-18T22:40:23.655+11:002011-03-18T22:40:23.655+11:00Petr,
He makes some good points. I listed some pr...Petr,<br /><br />He makes some good points. I listed some problems I had with the interpretation in the post.<br /><br />I am now not so sure of the original interpretationChris Nedinhttps://www.blogger.com/profile/06978886926715669724noreply@blogger.comtag:blogger.com,1999:blog-5517176012861550589.post-56808342946775054002011-03-18T09:48:06.736+11:002011-03-18T09:48:06.736+11:00hi!
i've found this video, which i thoutght wa...hi!<br />i've found this video, which i thoutght was pretty good:<br /><br />http://www.youtube.com/watch?v=qNCBcywWntA<br /><br />(it has three parts)<br /><br />and after watching that, i thought it's clear it wasn't neither a cephalopod nor a mollusc, but reading this made me confused again.<br /><br />i am not a native speaker so i might got misinformed when watching the videos.<br /><br />what do you think about what the man says?Petrhttps://www.blogger.com/profile/06537642993606964893noreply@blogger.comtag:blogger.com,1999:blog-5517176012861550589.post-62269186026523653682011-03-06T18:36:41.223+11:002011-03-06T18:36:41.223+11:00Resemblance to the Anomalocaris is difficult to ig...Resemblance to the Anomalocaris is difficult to ignore: paired front limbs, round "mouth", two bulbous eyes, and two pairs of long undulating "wings". It's like a smoother, softer Anomalocaris. Coincidence, maybe, but who knows.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-5517176012861550589.post-48107971023453852532010-07-17T01:14:48.093+10:002010-07-17T01:14:48.093+10:00I'm a bit late coming across this, but it occu...I'm a bit late coming across this, but it occurs to me that from what we have seen in developmental biology, serially repeated structures can occur without necessitating that the organism is truly segmented. Monoplacophorans are the obvious mollusc example of this, with serially repeated structures but no clear indication of segments and no correspondence in the numbers of each type of structure that would suggest ancestral segmentation and loss of segment boundaries.Oikomanhttps://www.blogger.com/profile/06369480591050751916noreply@blogger.comtag:blogger.com,1999:blog-5517176012861550589.post-66573608545472899282010-06-06T10:00:20.757+10:002010-06-06T10:00:20.757+10:00Well the oldest mollusc we have (albeit not fully ...Well the oldest mollusc we have (albeit not fully accepted) is <i>Kimberella</i> from the Ediacaran. That has what has been interpreted as serially repeated gill-like structures. Segmentation also appears in other Ediacaran forms such as <i>Dickinsonia</i> and <i>Spriggina</i>. even <i>Tribrachidium</i>appears to have a tripartite division. Also segmentation is ubiquitous in the stem arthropods. Even The horseshoe crab fossils from the latest ordovician find I blogged on last week has a form with fully segmented opisthosoma. So it's not a stretch to think that the last common ancester was a segmented form.Chris Nedinhttps://www.blogger.com/profile/06978886926715669724noreply@blogger.comtag:blogger.com,1999:blog-5517176012861550589.post-59211334509472720692010-06-06T00:35:40.239+10:002010-06-06T00:35:40.239+10:00What leads to the conclusion that the CA of arthro...What leads to the conclusion that the CA of arthropodes and molluscs was segmented? I'd understand the hypothesis that segmentation is a synapomorphy of molluscs and annelids, but is there a reason to push it further down (i.e. to include both ecdysozoa and lochotrophozoa)?Ralf Muschallhttps://www.blogger.com/profile/04261178237250734174noreply@blogger.com