There is a world somewhere between reality and fiction. Although ignored by many, it is very real and so are those living in it. This forum is about the natural world. Here, wild animals will be heard and respected. The forum offers a glimpse into an unknown world as well as a room with a view on the present and the future. Anyone able to speak on behalf of those living in the emerald forest and the deep blue sea is invited to join.
--- Peter Broekhuijsen ---

  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
The simbakubwa, a giant Miocene lion.

United States tigerluver Offline
Feline Expert
*****
Moderators
#28
( This post was last modified: 05-12-2019, 02:10 AM by tigerluver )

Had some time to read up on this new find. While likely large, the size here may be heavily over-exaggerated. 

Starting with the estimation itself, note there are three estimates: one by Morlo (1308 kg), another by Van Valkenburgh (VV) for felids (1554 kg), and finally Van Valkenburgh for carnivoras >100 kg (280 kg). 

Morlo's (1999) equation has extremely overestimated other more complete specimens of creodonts. The equation is extremely positively allometric (scale factor 3.5104), thus running the innate risk of hefty, hefty overestimation. 

The VV equation for felids simply is not valid here. Felids have proportionately much, much smaller skulls compared to their bodies than creodonts. Using a felid based equation to estimate the big toothed, extremely long headed creodont will give a very inaccurate and over-exaggerated value.

Note H. sulzeri (MNHN.F.Or 311-51) estimates in this paper (Morlo: 1276 kg; VV1: 1185 kg). Now let's take a look at the post-cranial remains of the same specimen (I've also added the table so we can see how H. sulzeri compares in bone measurements to Simbakubwa:


*This image is copyright of its original author

Based on the scale bars, the ulna measures just about 320 mm and humerus' distal articular width a bit less than 60 mm. These values are no larger than the size of a small-medium lioness (150 kg). Knowing that postcranial remains are always more accurate than cranial remains, the only conclusion that is to be made is that the Morlo and VV equation have overstimated H. sulzeri by 8 times. Seeing how H. sulzeri is a bit smaller than Simbakubwa, a mass of 1500 kg just does not seem accurate for Simbakubwa.

I will skip over the second VV equation as universal equations are not accurate as a single line cannot simply account for all the variations we see in species.

Next we have the associated long bones themselves. The authors state they believe the long bones from the same locality as the jaw do not belong to Simbakubwa despite the original assignment to the same individual as the mandible by the finders of the fossils. These fossils were collected close to one another. Sorkin also believed these were from the same individual. I will leave that decision to the reader. Nonetheless, here are the specimens:


*This image is copyright of its original author


The humerus and ulna are both about 330 mm. In both cases somewhat smaller than the average male lion. If we accept these specimens as Simbakubwa, we see these specimens are a bit larger than H. sulzeri, as predicted by the dental comparisons.

The authors do acknowledge the uncertainty of estimate in the work. Here we can see how skewed estimate can be when comparing one taxa to another. Simbakubwa clearly had a bigger head than a lion, but it probably was not any bigger.
4 users Like tigerluver's post
Reply




Messages In This Thread
RE: The simbakubwa, a giant Miocene lion. - tigerluver - 05-12-2019, 02:09 AM



Users browsing this thread:
1 Guest(s)

About Us
Go Social     Subscribe  

Welcome to WILDFACT forum, a website that focuses on sharing the joy that wildlife has on offer. We welcome all wildlife lovers to join us in sharing that joy. As a member you can share your research, knowledge and experience on animals with the community.
wildfact.com is intended to serve as an online resource for wildlife lovers of all skill levels from beginners to professionals and from all fields that belong to wildlife anyhow. Our focus area is wild animals from all over world. Content generated here will help showcase the work of wildlife experts and lovers to the world. We believe by the help of your informative article and content we will succeed to educate the world, how these beautiful animals are important to survival of all man kind.
Many thanks for visiting wildfact.com. We hope you will keep visiting wildfact regularly and will refer other members who have passion for wildlife.

Forum software by © MyBB