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Post by grrraaahhh on Mar 12, 2011 12:27:00 GMT -9
Good news everyone. Collection of materials on the Americas GSFB HEAVYWEIGHTS have met with good success. Many of us have been following with strong interest the latest material covering Arctotherium angustidens. The new data on the giant South American specimen inspired me to double check and dig around for material on its comparable sized North American cousins; the Giant Short Faced Bear (A. simus). By my count, there are a handful of fossil specimens that are comparable in scope, however, the heavier build advantage goes to the South American bear. They include a northern Californian specimen with a record size ulna measurement of 591 mm; the Lake Bonville, Utah specimen with a record size femur measurement of 723 mm; a Kansas specimen with a record size humerus measuring 646 mm; a Cass County (Nebraska) specimen with a humerus measurement of 633 mm, and another large Nebraska specimen from Hay Springs. Although less revealing, a future review (to better cross reference) of skull and dental data is warranted and planned. How would a completed Gold Run Creek, Yukon Territory (record size skull find) specimen compare to some of its larger cousins? Back to our original theme and to wrap up things, unpublished photos (i.e., our northern California specimen), plus illustrations (e.g., the Cass County, NE humerus) and material data have been collected and are being organized. Stay tuned...
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Post by grrraaahhh on Mar 17, 2011 21:12:05 GMT -9
Sorry for the delay (busy schedule, material collection & organizing, etc) but I wanted to get things rolling here. First some updates, I was hoping and I am still trying to obtain fossil photos for two large Arctodus simus specimens one of them from Kansas and the other from Hay Springs, Nebraska. My efforts have led me to conclude that there has been no published photo release of these two specimens. Now for the good news - we will have a forum milestone of sorts. I did find success in obtaining photos for the Irvingtonian (Alameda, CA) specimen. FYI, there has been no published release of photos for the Irvingtonian specimen. Photos for the Cass County humerus and Lake Bonneville femur have been acquired (the Utah specimen can be found online if you look hard enough). What I am providing here is a humerus and femoral fossil comparison table for the largest A.simus & A.angustidens’ specimens. As the data reveals, although there are North American A.simus specimens that produce longer humerus values, a review of the mid shaft width values tell us that A.angustidens is the heavier built bear. Comparable femoral data suggest a similar conclusion. The closest North American specimen to approach A.angustidens relative to robusticity is the specimen from Kansas. In the North American theater, the Kansas River specimen produced a higher mid shaft width femoral values than both the Lake Bonneville and Hay Springs bears. Moreover, the Kansas specimen produces a longer humerus than the Cass County, Nebraska GSFB. Stay tuned....
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Post by grrraaahhh on Apr 21, 2011 6:23:24 GMT -9
Update: With the exception of the Hay Springs sample, all other specimen material have been obtained.
Stay tuned...
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Post by grrraaahhh on Aug 11, 2011 4:44:05 GMT -9
Coming soon folks (sorry for the long delay) but attempts were made to obtain professional assistance to help scale the different photographs but these attempts were not successful. What will be provided shortly will nonetheless prove satisfactory for all.
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Post by grrraaahhh on Aug 11, 2011 4:45:53 GMT -9
As promised......
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Post by warsaw on Aug 11, 2011 6:10:22 GMT -9
As promised...... Thanks.
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Post by grrraaahhh on Aug 12, 2011 1:08:34 GMT -9
Thank you for the recognition. All, there is more to come. As I am traveling, I hope to visit NYC (time permitting) in the not so distant future to take photos of a large GSFB fossil femur. If I am successful, forum plans are to produce similar data which would include the top-3 largest GSFB fossil femur (2 of 3 have been accessed) & the top-3 largest GSFB fossil ulna (already obtained). Stay tuned.....
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Post by grrraaahhh on Aug 13, 2011 2:54:12 GMT -9
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Post by tremarctinae on Oct 3, 2011 12:42:46 GMT -9
The data you have collected are wonderful, thanks!
I have a few questions please:
1. there are 6 large specimens of arctodus simus, the 6 specimens you provided are KUVP C-2427, Cass county Nebraska, KUVP 131586, UVP 015/1, Hay Springs and UC 44687, right?
KUVP C-2427 seems to have the longest humerus but UVP 015 seems to have the longest femoral. So these bones are different, so we can't claim which is the biggest specimen of arctodus simus?
2. i have been searching informations for a lot of weeks to try reconstructing the real height of UVP/015 when it is standing up but i failed. So please, you know very well bears, can you give me an approximation of the height of UVP 015 at the shoulders and when it is standing up?
3. I have compared 2 skeletons between ursus arctos and short faced bear. They have the same number of vertebrae: why giant brown bears like goliath (12 feets tall right?) or super giant brown bears from russia in the early 20th century (with skins around 350 cm from the nose to the tail involving a height perhaps more than 3,7 meters) are taller than arctotherium angustidens?
Thanks a lot for your comments.
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Post by grrraaahhh on Oct 3, 2011 17:45:37 GMT -9
The data you have collected are wonderful, thanks! I have a few questions please: 1. there are 6 large specimens of arctodus simus, the 6 specimens you provided are KUVP C-2427, Cass county Nebraska, KUVP 131586, UVP 015/1, Hay Springs and UC 44687, right? KUVP C-2427 seems to have the longest humerus but UVP 015 seems to have the longest femoral. So these bones are different, so we can't claim which is the biggest specimen of arctodus simus? 2. i have been searching informations for a lot of weeks to try reconstructing the real height of UVP/015 when it is standing up but i failed. So please, you know very well bears, can you give me an approximation of the height of UVP 015 at the shoulders and when it is standing up? 3. I have compared 2 skeletons between ursus arctos and short faced bear. They have the same number of vertebrae: why giant brown bears like goliath (12 feets tall right?) or super giant brown bears from russia in the early 20th century (with skins around 350 cm from the nose to the tail involving a height perhaps more than 3,7 meters) are taller than arctotherium angustidens? Thanks a lot for your comments. The earlier humerus data make up the top four (three bears total) GSFB largest humerus fossils. Two bears are from North America, the other & heaviest bear is from Argentina. KUVP 131586: Regrettably, the distal end for this left femur is missing so the incomplete data was ignored. UC 44686 (the longest GSFB ulna fossil):Ulna measurementsA: 591 B: - C: 65 D: 47 E: 35.2 A. Greatest Length. B. Proximal diameter from tip of coronoid progress to Margo dorsalis. C. Smallest diameter from bottom of semi circular notch to Margo dorsalis.. D. Inner diameter of semi circular notch. E. Least transverse diameter of shaft, above capitulum. UC 44687 (2nd total length GSFB femur)Femur Measurements:A. 678 B. a165 C. 77 D. 62 E1. 134 A. Greatest Length. B. Greatest proximal width. C.Caput diameter. D. Least transverse width of shaft. E1. Greatest distal width over epicondyles. Source: Kurten (1967). Both CA specimen unpublished photos have been obtained & plans are to publish them later similar to the earlier humerus figure material. Ideally, I was hoping to obtain photos for the Hay Springs bear for a comprehensive publication but travel issues & scheduling conflict have complicated matters. Femoral measurements (1st in total length GSFB femur fossil):UVP 015 Lake Bonville, Utah Specimen & Material:UVP 015/1 Greatest length: 723 Greatest proximal width: 191 Caput diameter: - Least transverse width of shaft: 64 Greatest distal width over condyles: 152 shaggygod.proboards.com/index.cgi?board=americaspleistocene&action=display&thread=329&page=2See reply # 22. Keep in mind, different fossil models produce different weight estimates. There are some data I want to review. I will try to follow up more shortly.
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Post by tremarctinae on Oct 4, 2011 2:54:02 GMT -9
Unfortunately, we can't read the paper, only the first page is accessible... Well, i noticed that the short faced bear skeleton on boneclones (http://www.boneclones.com/images/sc-114-a-lg.jpg) is based on a 25 inches femur (63,5cm) and a 22 inches humerus(55,88cm) and this reconstitued specimen is 12 feet tall (3,65 meters). So can we conclude that UVP 015 which has a femoral of 72cm in length is taller than 3,65 meters? You have probably noticed that arctotherium angustidens is supposed 3,4 meters standing up with a humerus of 62 cm in length... I am getting desperate nobody can't give me some explanations with this measures...(it's absolutely not a critic of course ) Thanks.
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Post by grrraaahhh on Oct 4, 2011 18:32:05 GMT -9
Unfortunately, we can't read the paper, only the first page is accessible... Well, i noticed that the short faced bear skeleton on boneclones (http://www.boneclones.com/images/sc-114-a-lg.jpg) is based on a 25 inches femur (63,5cm) and a 22 inches humerus(55,88cm) and this reconstitued specimen is 12 feet tall (3,65 meters). So can we conclude that UVP 015 which has a femoral of 72cm in length is taller than 3,65 meters? You have probably noticed that arctotherium angustidens is supposed 3,4 meters standing up with a humerus of 62 cm in length... I am getting desperate nobody can't give me some explanations with this measures...(it's absolutely not a critic of course ) Thanks. The Soibelzon and Blaine 2011 Arctotherium angustidens article is subscription access only. If you enjoy university access a lot of your questions can be answered as they are addressed in numerous articles almost all of them subscription based. RE: boneclones estimate/data - I would not place much stock in it, here, professional paleontologist data trumps all. Remember, they are profit driven and a little hyperbole will help their bottom line (don't believe everything you read). FYI, conventional professional accounts for bipedal height for mature/large GSFB is 3.4 meters.
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Post by grrraaahhh on Oct 5, 2011 19:02:24 GMT -9
The data you have collected are wonderful, thanks! I have a few questions please: 1. there are 6 large specimens of arctodus simus, the 6 specimens you provided are KUVP C-2427, Cass county Nebraska, KUVP 131586, UVP 015/1, Hay Springs and UC 44687, right? KUVP C-2427 seems to have the longest humerus but UVP 015 seems to have the longest femoral. So these bones are different, so we can't claim which is the biggest specimen of arctodus simus? 2. i have been searching informations for a lot of weeks to try reconstructing the real height of UVP/015 when it is standing up but i failed. So please, you know very well bears, can you give me an approximation of the height of UVP 015 at the shoulders and when it is standing up? 3. I have compared 2 skeletons between ursus arctos and short faced bear. They have the same number of vertebrae: why giant brown bears like goliath (12 feets tall right?) or super giant brown bears from russia in the early 20th century (with skins around 350 cm from the nose to the tail involving a height perhaps more than 3,7 meters) are taller than arctotherium angustidens? Thanks a lot for your comments. The earlier humerus data make up the top four (three bears total) GSFB largest humerus fossils. Two bears are from North America, the other & heaviest bear is from Argentina. KUVP 131586: Regrettably, the distal end for this left femur is missing so the incomplete data was ignored. UC 44686 (the longest GSFB ulna fossil):Ulna measurementsA: 591 B: - C: 65 D: 47 E: 35.2 A. Greatest Length. B. Proximal diameter from tip of coronoid progress to Margo dorsalis. C. Smallest diameter from bottom of semi circular notch to Margo dorsalis.. D. Inner diameter of semi circular notch. E. Least transverse diameter of shaft, above capitulum. UC 44687 (2nd total length GSFB femur)Femur Measurements:A. 678 B. a165 C. 77 D. 62 E1. 134 A. Greatest Length. B. Greatest proximal width. C.Caput diameter. D. Least transverse width of shaft. E1. Greatest distal width over epicondyles. Source: Kurten (1967). Both CA specimen unpublished photos have been obtained & plans are to publish them later similar to the earlier humerus figure material. Ideally, I was hoping to obtain photos for the Hay Springs bear for a comprehensive publication but travel issues & scheduling conflict have complicated matters. Femoral measurements (1st in total length GSFB femur fossil):UVP 015 Lake Bonville, Utah Specimen & Material:UVP 015/1 Greatest length: 723 Greatest proximal width: 191 Caput diameter: - Least transverse width of shaft: 64 Greatest distal width over condyles: 152 shaggygod.proboards.com/index.cgi?board=americaspleistocene&action=display&thread=329&page=2See reply # 22. Keep in mind, different fossil models produce different weight estimates. There are some data I want to review. I will try to follow up more shortly. Body Mass Estimation- There have been few attempts to estimate the size of the ‘short-faced’ bear. Where estimates were made, often the sample size was small.
- Limb bones are responsible for supporting the animal’s weight during locomotion (Anyonge, 1993; Christiansen and Harris, 2005), thus providing the best mass estimates for extinct species. Kurt´en (1967) used the reconstructed body length and the cross-sectional area of a femoral diaphysis of a large specimen from Hay Springs for calculating its mass as between 470 and 630 kg.
- Employing Kurt'en's method, Nelson and Madsen (1983) obtained an estimate of 620–660 kg for the specimen UVP 015 from Salt Lake County (Northern Utah), based on the diaphyseal area of the femur.
- Christiansen (1999b) used several measurements taken in the proximal limb bones to estimate the mean mass of three specimens of A. simus as ca. 770 kg.
Figueirido et al. (2010) measured the maximum length and least width of the diaphyseal shaft of each major limb bone in a data set of 58 specimens of the eight species of extant ursids. Log-transformed data were used for calculating least squares bivariate regression functions of body mass on each measurement. For each bear species, we used published estimates of average mass (Van Valkenburgh, 1990; Christiansen, 1999b, 2002; Egi, 2001; Anderson, 2004). The accuracy of the bivariate regression functions was evaluated from their percent prediction errors (%PE) and the percent standard error of the estimates (%SEE) following Smith (1981, 1984). Approximately one third of specimen body mass estimates approached one tonne - the author further speculates that bears of this size were more common than previously suspected.
- Soibelzon and Schubert (2011) obtained body mass of South American short-faced bears following the estimates by Soibelzon and Tartarini (2009) employing the allometric equations published by other authors (e.g., Van Valkenburgh,1990; Anyonge, 1993; Viranta, 1994; Christiansen, 1999; Egi, 2001). The study by Soibelzon and Tartarini (2009) compared more than sixty equations based on teeth, skull and postcranial measurements, and found the most reliable predictor of body size for large specimens was six measurements of the humerus (proposed by Anyonge, 1993; Egi, 2001; Christiansen, 1999) and one on the radius (formulated by Viranta, 1994) (for more details see Soibelzon and Tartarini, 2009). Thus, the size of the individual described here is estimated based on the preserved humerus and radius using these seven equations. The result, the Argentine specimen had an estimated body mass ranging from 983 to 2,042 kg depending on the equations considered while the mean and median body mass estimates (considering all equations) were 1,588 and 1,749 kg respectively.
More to come.....
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