JoyH Posted October 21, 2015 Share Posted October 21, 2015 At what size does a fossil move from macro to micro? I recently collected a tiny baculite that requires magnification to see the details and I am not sure which category it falls into. Please forgive the quality of the photos. Link to comment Share on other sites More sharing options...
sdsnl Posted October 21, 2015 Share Posted October 21, 2015 https://en.wikipedia.org/wiki/Micropaleontology "Microfossils are fossils generally not larger than four millimeters, and commonly smaller than one millimeter, the study of which requires the use of light or electron microscopy." 1 Link to comment Share on other sites More sharing options...
TNCollector Posted October 21, 2015 Share Posted October 21, 2015 Technically,sdsnl has the right answer, but personally my microfossil collection is anything below about 7mm. I would not call your specimen micro. Cool find though! Link to comment Share on other sites More sharing options...
JoyH Posted October 21, 2015 Author Share Posted October 21, 2015 (edited) Thank you. These are exactly the type of answers I was looking for. Honestly, I didn't think my baculite qualified, but it made me curious and pictures always help. Edited October 21, 2015 by JoyH Link to comment Share on other sites More sharing options...
Ridgehiker Posted October 21, 2015 Share Posted October 21, 2015 It's a subjective term. A bit like saying what is the difference between something being big or small...it depends. What is the difference between a small and a big fossil? We never used the terms in any research we did. Certain small fossils such as conodonts, ostracods, foraminifera were used in biostratigraphy studies. However some of these may be larger than other phyla in which the specimens are usually bigger. What some institutes have is a prep lab that is assigned the extraction and preparation of certain types of small fossils (conodonts, etc). These are then given back to a researcher who will use them to help date rocks, determine climate conditions, etc. Yes, they usually need the use of a microscope for study but so do thin sections, peels, etc. of most large fossils. 1 Link to comment Share on other sites More sharing options...
Auspex Posted October 23, 2015 Share Posted October 23, 2015 It gets a little murky because, in part, we use high magnification to study details in a large fossil. Your baculite might be a small example, but you can tell what it is without magnification; it is the details that require a loupe. "There has been an alarming increase in the number of things I know nothing about." - Ashleigh Ellwood Brilliant “Try to learn something about everything and everything about something.” - Thomas Henry Huxley >Paleontology is an evolving science. >May your wonders never cease! Link to comment Share on other sites More sharing options...
MarcoSr Posted October 23, 2015 Share Posted October 23, 2015 I define what is micro and macro a little less scientifically. If I can find the specimen in a sift as small as 1/4" or regular surface collecting I consider the specimen macro. If I can only find it through a bulk sampling method than to me it is a micro. Specimens that I find crawling on hands and knees with my face to the ground are in a gray area. But I agree a size definition or the need to use magnification to study details are better definitions. Marco Sr. 1 "Any day that you can fossil hunt is a great day." My family fossil website Some Of My Shark, Ray, Fish And Other Micros My Extant Shark Jaw Collection Link to comment Share on other sites More sharing options...
Mediospirifer Posted October 23, 2015 Share Posted October 23, 2015 I tend to go with 1/4" as a dividing line. This means some of my Tornoceras ammonites are micros, and some are not. Likewise for Cincinnetina and Dalmanella brachiopods. Every dividing line drawn in biology has edge cases, where "which side of the line do we call this specimen on?" can be argued about. I'm willing to be flexible about it for the purposes of discussion. Link to comment Share on other sites More sharing options...
reddesilets Posted October 23, 2015 Share Posted October 23, 2015 (edited) I'm extremely new to this and when I'm talking about collecting in my area, which is usually things like shark teeth, bones, vertebrae, etc. I have personally used the term "micro" to mean anything that passes through a 1/4" screen, as others have indicated, but it's certainly not the use I would anticipate in any other setting. I'm actually glad to see other people commenting they use it the same way. I should add that I don't think I have the equipment to find, process, photograph and catalog/store true micros. Edited October 23, 2015 by reddesilets "Direct observation of the testimony of the earth ... is a matter of the laboratory, of the field naturalist, of indefatigable digging among the ancient archives of the earth's history." — Henry Fairfield Osborn Link to comment Share on other sites More sharing options...
Herb Posted October 26, 2015 Share Posted October 26, 2015 generally , anything you need a microscope to identify, is a microfossil. "Absence of evidence is not evidence of absence"_ Carl Sagen No trees were killed in this posting......however, many innocent electrons were diverted from where they originally intended to go. " I think, therefore I collect fossils." _ Me "When you have eliminated the impossible, whatever remains, however improbable, must be the truth."__S. Holmes "can't we all just get along?" Jack Nicholson from Mars Attacks Link to comment Share on other sites More sharing options...
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