15 replies to this topic

[Antennal_Scrobe]

Titanomyrma gigantea was a colossal ant species which lived during the Eocene. We have fossils of its queens, which grew up to 2.4 inches long, and its males, which grew to 1.2 inches. The species did not have a sting and somewhat resembles a modern formicine. Other than that, we know nothing of its biology. What did its workers look like? How big were they? What did they eat? To start off, I highly doubt that they were army ants of any kind, as their queens dispersed normally with wings, and otherwise resembled bigger versions of the ones we find. Army ant queens look like swollen termite queens and have no wings or eyes, instead breaking off from their mother colonies with about half the workers. I'll also say that I don't think they were polygynous either. Polygynous species tend to have tiny queens, not hummingbird sized ones. Just look as the strictly monogynous Camponotus pennsylvanicus, and then at the polygynous Formica montana. We could go with my buzzkill theory that the workers were 1 millimeter long like in Carebara castanea, which has huge queens but tiny workers. What do you guys think?

[Antennal_Scrobe]

Minor workers of Dinomyrmex gigas, a pretty good analog for Titanomyrma, are about two thirds the size of the queens, giving us a worker size of 1.5 inches for Titanomyrma. The majors of the aforementioned modern ant are almost as long as the queens, though.

[TennesseeAnts]

I read about these in an old paper.

[Antennal_Scrobe]

Fascinating, right? A whole subfamily of enigmatic and huge ants that just disappeared.

[AntsDakota]

Too bad we didn't have Jurassic Park/World technology. They would be so fun to keep.....

[TennesseeAnts]

Fascinating, right? A whole subfamily of enigmatic and huge ants that just disappeared.

Probably couldn't handle the earth's drastic change in oxygen levels. Those larger insects require about 90% oxygen if I remember correctly.

[Antennal_Scrobe]

I think the oxygen levels that enabled the big Carboniferous Arthropods were around 31 percent if I remember correctly. The Eocene, when these ants lived, had really high CO2, and was a hot tropical time period. I don't know if oxygen played a part given that there are insects around today which are much larger than Titanomyrma. 

Edited by Antennal_Scrobe, September 2 2019 - 2:34 PM.

[TennesseeAnts]

Yeah I don't know where I heard that, but it was a while ago.

[Antennal_Scrobe]

Yeah the Eocene apparently had a big ice age at the end when it transitioned to the Oligocene. That obviously is pretty bad if you're used to no ice and balmy weather all year long. What a shame.

[ponerinecat]

[Antennal_Scrobe]

Oh! Thanks ponerinecat!

[ponerinecat]

Welcome. Not my pic.

[AntHUB]

Titanomyrma gigantea was a colossal ant species which lived during the Eocene. We have fossils of its queens, which grew up to 2.4 inches long, and its males, which grew to 1.2 inches. The species did not have a sting and somewhat resembles a modern formicine. Other than that, we know nothing of its biology. What did its workers look like? How big were they? What did they eat? To start off, I highly doubt that they were army ants of any kind, as their queens dispersed normally with wings, and otherwise resembled bigger versions of the ones we find. Army ant queens look like swollen termite queens and have no wings or eyes, instead breaking off from their mother colonies with about half the workers. I'll also say that I don't think they were polygynous either. Polygynous species tend to have tiny queens, not hummingbird sized ones. Just look as the strictly monogynous Camponotus pennsylvanicus, and then at the polygynous Formica montana. We could go with my buzzkill theory that the workers were 1 millimeter long like in Carebara castanea, which has huge queens but tiny workers. What do you guys think?

I know this post is old but i'd like to comment on it:

Comparing titanomyrma to to other fossil gynes reveals that of all ants they are probably closer morphologically to dolichoderinae than most other subfamilies. Your buzz kill idea would make sense if they were myrmecines, but generally dolichoderine castes aren't very distinct. It's likely that the workers looked similar to a dolichoderine although we can't be sure. I did a review of some of the ants from the florissant formation (eocene lake) and almost everything is a dolichoderine. So we can guess that the workers could have been similar to aphaenogaster, but since it's actually a separate subfamily, who's to say. I don't know much but go check out my blog for some thoughts on eocene ants.

[Antennal_Scrobe]

 

Titanomyrma gigantea was a colossal ant species which lived during the Eocene. We have fossils of its queens, which grew up to 2.4 inches long, and its males, which grew to 1.2 inches. The species did not have a sting and somewhat resembles a modern formicine. Other than that, we know nothing of its biology. What did its workers look like? How big were they? What did they eat? To start off, I highly doubt that they were army ants of any kind, as their queens dispersed normally with wings, and otherwise resembled bigger versions of the ones we find. Army ant queens look like swollen termite queens and have no wings or eyes, instead breaking off from their mother colonies with about half the workers. I'll also say that I don't think they were polygynous either. Polygynous species tend to have tiny queens, not hummingbird sized ones. Just look as the strictly monogynous Camponotus pennsylvanicus, and then at the polygynous Formica montana. We could go with my buzzkill theory that the workers were 1 millimeter long like in Carebara castanea, which has huge queens but tiny workers. What do you guys think?

I know this post is old but i'd like to comment on it:

Comparing titanomyrma to to other fossil gynes reveals that of all ants they are probably closer morphologically to dolichoderinae than most other subfamilies. Your buzz kill idea would make sense if they were myrmecines, but generally dolichoderine castes aren't very distinct. It's likely that the workers looked similar to a dolichoderine although we can't be sure. I did a review of some of the ants from the florissant formation (eocene lake) and almost everything is a dolichoderine. So we can guess that the workers could have been similar to aphaenogaster, but since it's actually a separate subfamily, who's to say. I don't know much but go check out my blog for some thoughts on eocene ants.

 

Wow, thanks! I forgot all about this thread.

[AntsDakota]

 

 

Doesn't work for me.

[AntsDakota]

 I'll also say that I don't think they were polygynous either. Polygynous species tend to have tiny queens, not hummingbird sized ones. Just look as the strictly monogynous Camponotus pennsylvanicus, 

Well, Camponotus vicinus is oftentimes polygynous. In my experience they are a tiny bit larger than even pennsylvanicus.