Body mass amphicyonidae

[ursidae]

Here are some estimations about body mass in the extinct family amphicyonidae. There are 3 size groups: small, mid-sized and large. We can tell with certainty that this family generated carnivores larger than any felidae extant or extinct:

Small:

Paradaphoenus cuspigerus : 4 kg
Daphoenus hartshornianus: 10 kg
Daphoenus vetus: 27 kg
Daphoenodon skinneri: 40 kg

mid-sized:

Daphoenodon neomexicanus :135 kg
Daphoenodon falkenbachi : 137 kg
Pliocyon medius : 145 kg
Adilophontes brachykolos : 154 kg
Amphicyon major : 183 kg
Amphicyon galushai : 191 kg
Ischyrocyon gidleyi (Barstovian) : 194 kg

large:

Ysengrinia americana : 231 kg
Pseudocyon sansaniensis : 245 kg
Pseudocyon sp. (Nebraska) : 310 kg
Amphicyon frendens : 432 kg
Ischyrocyon gidleyi (Claredonian) :546 kg
Amphicyon ingens : 579 kg
Pseudocyon sp. (New Mexico) : 773 kg

Source: Body mass estimation in amphicyonid carnivoran
mammals: A multiple regression approach from the skull and skeleton. BORJA FIGUEIRIDO,JUANA. PÉRE−CLAROS,ROBERTM.HUNT, JR., andPAULPALMQVIST

Considering the fact that the highest value about mean mass for Ursus maritimus is 489 kg, and the fact that we have only a few bones of the largest amphicyionidae which are estimated well above 500 kg, i wonder if the largest amphicyonidae were more massive than the largest extant bears...
Surprisingly, the largest body mass estimation about amphicyon ingens is 1170 kg, larger than the highest value of arctodus simus UVP015...

[warsaw]

Aug 18, 2012 5:13:04 GMT -9 ursidae said:

Here are some estimations about body mass in the extinct family amphicyonidae. There are 3 size groups: small, mid-sized and large. We can tell with certainty that this family generated carnivores larger than any felidae extant or extinct:

Small:

Paradaphoenus cuspigerus : 4 kg
Daphoenus hartshornianus: 10 kg
Daphoenus vetus: 27 kg
Daphoenodon skinneri: 40 kg

mid-sized:

Daphoenodon neomexicanus :135 kg
Daphoenodon falkenbachi : 137 kg
Pliocyon medius : 145 kg
Adilophontes brachykolos : 154 kg
Amphicyon major : 183 kg
Amphicyon galushai : 191 kg
Ischyrocyon gidleyi (Barstovian) : 194 kg

large:

Ysengrinia americana : 231 kg
Pseudocyon sansaniensis : 245 kg
Pseudocyon sp. (Nebraska) : 310 kg
Amphicyon frendens : 432 kg
Ischyrocyon gidleyi (Claredonian) :546 kg
Amphicyon ingens : 579 kg
Pseudocyon sp. (New Mexico) : 773 kg

Source: Body mass estimation in amphicyonid carnivoran
mammals: A multiple regression approach from the skull and skeleton. BORJA FIGUEIRIDO,JUANA. PÉRE−CLAROS,ROBERTM.HUNT, JR., andPAULPALMQVIST

Considering the fact that the highest value about mean mass for Ursus maritimus is 489 kg, and the fact that we have only a few bones of the largest amphicyionidae which are estimated well above 500 kg, i wonder if the largest amphicyonidae were more massive than the largest extant bears...
Surprisingly, the largest body mass estimation about amphicyon ingens is 1170 kg, larger than the highest value of arctodus simus UVP015...

www.app.pan.pl/archive/published/app56/app20100005.pdf

[Ursus arctos]

The 1,170 kg estimate was based on the mandible measurements.
Limb bone measurements are probably more reliable than those of cranial features for estimating body mass.

If you use the Ursidae regression equation produced by Christiansen in "What size were Arctodus simus and Ursus spelaeus?" in 1999 for body mass vs humerus length, you get an estimate of 2,225 kg for the Arcotodus simus specimen KUVP C-2427.