A bone

[Shellseeker]

http://www.thefossilforum.com/index.php?/topic/82717-kem-kem-bone/

This link above has an interesting picture of an Alligator shoulder blade,  that I thought a little similar. Not broken,  a lot of detail... How come this one is difficult?  ....

[Megalodoodle]

I believe an international scale (like metric) is preferred.

[Shellseeker]

4 hours ago, Megalodoodle said:

I believe an international scale (like metric) is preferred.

Sure .  2.5 inches is 63.5 mm

[caterpillar]

Looks a croc coracoid

[pachy-pleuro-whatnot-odon]

13 hours ago, Megalodoodle said:

I believe an international scale (like metric) is preferred.

 

The most confusing part for me is typically determining whether I'm looking at inches or centimetres, as conversion from inches to cm is a simple multiplication by 2.54

[Shellseeker]

13 hours ago, pachy-pleuro-whatnot-odon said:

 

The most confusing part for me is typically determining whether I'm looking at inches or centimetres, as conversion from inches to cm is a simple multiplication by 2.54

Because of fossils, I can easily convert between millimeters and inches..and I try to provide both for fossils in MY possession. It is a reasonable accommodation and friendly gesture to my TFF friends from foreign countries.

However , some fossil photos come to me from Americans who have no clue what a millimeter is. The American use of metrics is non existant. A child might get a class or 2 on measurements that include millimeters and then return to a world based on inches and feet.

In this instance, politicians who made these agreements for Americans did not cover themselves in glory.

[Shellseeker]

16 hours ago, caterpillar said:

Looks a croc coracoid

Thank you,  I agree.

Finding a Croc bone in a Bone Valley PlioMiocene site would be exciting.  There have been a few crocs in the Florida Fossil record,  but Alligators dominate.

I will be trying to find a differentiator between Croc and Gator coracoid.  Once again Thanks, Jack

[pachy-pleuro-whatnot-odon]

7 minutes ago, Shellseeker said:

The American use of metrics is non existant. A child might get a class or 2 on measurements that include millimeters and then return to a world based on inches and feet.

 

That's what makes it so confusing, since, yes, I'm aware that Americans mostly use inches and feet. But I also know that most members on TFF try to accommodate for metric system (as do, I believe, many American international fossil dealers). Just from looking at a ruler, I find it hard rob day whether I'm looking at inches or cm. Like I said, the concretion is not that hard, so I don't mind getting my numbers in inches, just as long as I know that's what they are

[FossilDAWG]

14 hours ago, pachy-pleuro-whatnot-odon said:

 

The most confusing part for me is typically determining whether I'm looking at inches or centimetres...

I count the ticks between the numbers.  If it's 16 the scale is in inches.  If 10 it's metric.

 

Don

[pachy-pleuro-whatnot-odon]

1 minute ago, FossilDAWG said:

I count the ticks between the numbers.  If it's 16 the scale is in inches.  If 10 it's metric.

 

Hah! It must sound silly, but I didn't know that...! A very useful trick. Thanks! 

[Megalodoodle]

14 hours ago, pachy-pleuro-whatnot-odon said:

 

The most confusing part for me is typically determining whether I'm looking at inches or centimetres, as conversion from inches to cm is a simple multiplication by 2.54

I wonder how much accuracy is lost during the conversion?

[pachy-pleuro-whatnot-odon]

43 minutes ago, Megalodoodle said:

I wonder how much accuracy is lost during the conversion?

 

I'd say that depends on the accuracy of the original measurement, as both measurement systems are linear, and conversion can therefore proceed based on a multiplication factor. This is unlike the conversion between degrees Celcius and Fahrenheit, for example, since these record values on different scales and therefore need a formula for conversion.

 

However, if you're talking about a ruler measurement, every inch equates to 2.54cm, and each of its 16 parts to ~0.158cm (2.54/16), whereas each measure on a ruler in the metric system would record values at intervals of 0.1cm. The smaller number allows for taking measurements with higher accuracy, since when we round values up or down to the nearest partition on the ruler, the gaps are smaller and the value is therefore rounded less. As such, taking measurements in the metric system would, by this logic, result in more accurate readings.

 

As to potential loss of accuracy when taking measurements in inches versus centimetre, this would at most be (0.158-0.1)/2 = 0.029cm, since whenever taking a measurement from a ruler you'd always be able to say whether the measurement tends more towards the lower or higher marking on the ruler. Thus, half way between two markings is a neutral spot: either the actual measured value falls in the half 1/16 inch/mm below it, or the half above it. This means that when reading a measurement in inches, the maximum error in accuracy would be 0.079cm, and 0.05cm on a centimetre-scale. The differences in how accurate readings can be in the first place mean that if we look at the maximum error for inches and then for centimetres, the difference is 0.029cm. This, therefore, I believe, would be the maximum loss in accuracy resulting from the different measurement systems, rather than from just taking a measurement by ruler to start off. As 0.29mm is extremely small, I'd say that the inaccuracy is negligible, although it would probably be better to stick to no more than one decimal position when converting analogue measurements from inches to centimetres (unless using bracketing instead).

Edited February 8, 2022 by pachy-pleuro-whatnot-odon

[JohnJ]

46 minutes ago, Megalodoodle said:

I wonder how much accuracy is lost during the conversion?

Negligible, in this context.  

[Coco]

Hi,

 

I should point out that in the metric system, the measurements are indicated more in cm than in mm. For example, 1.75 cm instead of 17.5 mm.

 

Ah, another thing that may be important is that we put a comma between the cm and the mm, while the Americans put a dot. I made it the painful experience on our favorite auction site many years ago...

 

Coco