Recommended audio series on the natural history of the pampas

@tonyrebelo @jeremygilmore @ludwig_muller @matthewinabinett @paradoxornithidae @beartracker @dinofelis @yvettevanwijk1941 @karoopixie @botswanabugs @dianastuder

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https://www.youtube.com/watch?v=CyjECaII_ZA

https://www.youtube.com/watch?v=qN9upTIVC0Y

to be continued...

Posted on August 26, 2023 05:20 PM by milewski milewski

Comments

Many thanks for this series

Posted by paradoxornithidae 11 months ago

Thanks!

Posted by beartracker 11 months ago

The following were the genera of medium-size to large mammals (excluding those weighing one tonne or more) in the Lujanian fauna (of the Late Pleistocene) in what is now Buenos Aires province of Argentina.

Source: https://web.archive.org/web/20110706084815/http://www.ege.fcen.uba.ar/materias/general/Broken_ZigZagMACN_5_1_19_.pdf

*Asterisks show families that are wholly extinct

ARTIODACTYLA https://www.researchgate.net/publication/331071363_Evolutionary_History_of_South_American_Artiodactyla

Cervidae:
Antifer (deer, https://www.theextinctions.com/antifer and https://prehistoric-wiki.fandom.com/wiki/Antifer and https://onlinelibrary.wiley.com/doi/abs/10.1002/jmor.21243)
Paraceros (deer, https://noticiasdepaleontologia.blogspot.com/2019/08/hallan-el-primer-craneo-de-paraceros.html)
Morenelaphus (deer, ?200 kg, https://www.sciencedirect.com/science/article/abs/pii/S0031018217306107#:~:text=Abstract,and%20the%20broadest%20geographic%20distribution.)

Camelidae (https://www.alpacaconsultingusa.com/library/CamelidOriginEvolution.pdf):
Eulamaops (150 kg, similar in size to extant guanaco)
Lama (genus still extant, https://en.wikipedia.org/wiki/Lama_(genus) and https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8032396/#:~:text=Llama%20and%20alpaca%20first%20appeared,1984%3B%20Wheeler%2C%201995).)
Palaeolama (forest camelid, 200 kg)

Tayassuidae:
Catagonus (peccary, https://en.wikipedia.org/wiki/Catagonus_carlesi and https://ielc.libguides.com/sdzg/factsheets/chacoanpeccary/taxonomy)

PERISSODACTYLA

Tapiridae:
Tapirus (tapir, no larger than modern spp., https://link.springer.com/article/10.1007/s10914-012-9196-z and https://bioone.org/journals/acta-palaeontologica-polonica/volume-57/issue-3/app.2011.0001/Tapirs-from-the-Pleistocene-of-Venezuela/10.4202/app.2011.0001.full)

Equidae (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1159165/):
Equus (horse/zebra, 400 kg, https://en.wikipedia.org/wiki/Equus_neogeus#:~:text=Equus%20neogeus%20is%20an%20extinct,closely%20related%20to%20true%20horses.)
Hippidion (horse-like, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4387498/ and https://en.wikipedia.org/wiki/Hippidion)

LIPOPTERNA

*Macraucheniidae (https://en.wikipedia.org/wiki/Macraucheniidae):
Xenorhinotherium (>800 kg, https://www.theextinctions.com/xenorhinotherium-bahiense)

RODENTIA

Caviidae:
Neochoerus (giant capybara, possibly not tied to water, ?100 kg, https://ielc.libguides.com/sdzg/factsheets/extinctpinckneyscapybara/characteristics and https://en.wikipedia.org/wiki/Hydrochoerinae)

PILOSA

*Nothrotheriidae:
Nothropus (ground sloth)
Nothrotherium (ground sloth)

*Megatheriidae
Ocnopus (ground sloth)

*Mylodontidae:
Ocnotherium (ground sloth)

*Scelidotheriidae:
Scelidodon (ground sloth)
Scelidotherium (ground sloth)
Valgipes (ground sloth)

CINGULATA

*Pampatheriidae:
Holmesina (giant armadillo, 200 kg)
Pampatherium (giant armadillo up to 200 kg)

Dasypodidae:
Propraopus (relative of extant armadillos, https://www.researchgate.net/publication/259141064_The_armadillo_Propraopus_sulcatus_Mammalia_Xenarthra_from_the_late_Quaternary_of_northern_Brazil_and_a_revised_synonymy_with_Propraopus_grandis)

*Chlamyphoridae:
Eutatus (glyptodont)
Glyptotherium (glyptodont)
Hoplophorus (glyptodont)
Neuryurus (glyptodont)
Parapanochthus (glyptodont)
Neosclerocalyptus (glyptodont)

CARNIVORA

Felidae:
Smilodon populator (sabre-tooth cat, >300 kg)

Ursidae:
Arctotherium (deep-jawed bear, 250 kg)

Canidae:
Aenocyon (wolf, 65 kg, https://en.wikipedia.org/wiki/Canis_nehringi and https://en.wikipedia.org/wiki/Dire_wolf and https://prehistoric-fauna.com/Aenocyon-dirus)
Dusicyon (dog-like, 30 kg)
Protocyon (dog-like, 30 kg)

PRIMATES

Atelidae:
Protopithecus (monkey, 23 kg)

Posted by milewski 11 months ago

We saw, in part 2 of the pampas series of audio podcasts, that the only familiar family, among the various megaherbivores (body mass > 10 tonne = 1,000 kg) of the Lujanian fauna of Buenos Aires province, was the Camelidae.

All the other megaherbivores here, ranging from elephant-like gomphotheres through giant ground sloths and glyptodonts to notoungulates and a litoptern, belong to now-extinct families.

When it comes to the mammals of 20-999 kg in the same fauna, there are more familiar elements, because the extinctions have not been as profound.

Genera which survive - albeit only elsewhere - in modern times are Lama, Catagonus (https://en.wikipedia.org/wiki/Catagonus), Equus, and Tapirus.

There is even more familiarity at the level of families. The Lujanian mammals of 20-999 kg included deer (Cervidae), camels (Camelidae), peccaries (Tayassuidae), equids (Equidae), tapirs (Tapiridae), cats (Felidae), bears (Ursidae), dogs (Canidae), armadillos (Dasypodidae), cavies (Caviidae), and atelid monkeys (Atelidae).

This leaves seven families, in this body mass-range, that are as unfamiliar as in the case of the megaherbivores. These are mainly xenarthran ('edentate') families, plus the litoptern family Macraucheniidae - the latter belonging to an extinct order.

As in the case of the megaherbivores, the xenarthrans of < 1 tonne have so many sympatric genera that it is hard to imagine how they all coexisted.

I refer to seven genera (in four families) of Pilosa (ground sloths), and nine genera (in three families including two extinct families) of Cingulata. Glyptodonts belong to Chlamyphoridae, and pampatheres belong to Pampatheriidae.

Posted by milewski 11 months ago

Canis dirus has now been classified as Aenocyon dirus, with the Aenocyon lineage being closer to Lupulella than Canis, if I'm not mistakened.

Posted by paradoxornithidae 11 months ago

@paradoxornithidae

Many thanks for correcting my inexcusable error. It is indeed significant that dire wolves were distinct from Canis, much as sabre-tooth cats were distinct from Panthera.

Posted by milewski 11 months ago

Apparently Lycalopex gymnocercus (Pampas fox) can hybridise with Canis familiaris (domestic dog) (source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10417603/)

Posted by paradoxornithidae 11 months ago

If this was possible, one can suppose Aenocyon dirus could've hybridised with Canis lupus.

Posted by paradoxornithidae 11 months ago

@paradoxornithidae

Many thanks for pointing this out.

It seems significant that a species of Lycalopex is the closest thing to a coyote in South America (https://www.inaturalist.org/journal/milewski/67242-concise-photo-guide-to-the-jackals-of-the-world#).

The failure of the coyote to invade South America is usually taken for granted. However, it is noteworthy, and partly explained by the view that Lycalopex takes the place of Canis in South America, with a similar niche as well as enough phylogenetic similarity that intergeneric hybridisation remains possible. The real surprise is, perhaps, that the hybridisation was not with Lycalopex culpaeus.

As for hybridisation between Canis and Aenocyon, this does indeed seem possible. The clearest morphological distinction between the two genera seems to be in the baculum (https://www.facebook.com/SmithsonianNMNH/photos/the-extinct-dire-wolf-canis-dirus-was-once-common-across-the-americas-and-is-a-d/10156412802378230/ and https://www.researchgate.net/figure/Canis-dirus-bacular-ontogenetic-stage-scores-compared-with-the-baculum-of-C-lupus_fig3_301866914 and https://www.sciencedirect.com/science/article/abs/pii/S1047847711001729).

Because this is the bone in the penis (https://www.researchgate.net/figure/Cross-section-through-the-penis-of-a-dog-Canis-familiaris-modified-according-to_fig6_264718877), this may indicate a mode of reproductive separation notwithstanding the genetic compatibility.

Please bear in mind that canids have a copulatory tie, so the form of the penis may matter.

Putting this differently:

If one were to perform artificial insemination, probably there would be no problem crossing Aenocyon with Canis, producing fertile offspring, and blurring the genera. And possibly such blurring actually happened in nature just before Aenocyon went extinct. However, a barrier to hybridisation possibly exists in the form and function of the genitals, analogous to a 'lock-and-key' mechanism.

https://www.facebook.com/ejwillinghamphd/photos/a.2343614119031481/3329379133788303/?type=3

https://www.flickr.com/photos/baggis/4670750803

https://twitter.com/ashinonyx/status/1228438759588364288

https://escholarship.org/uc/item/96j439rz

https://zslpublications.onlinelibrary.wiley.com/doi/abs/10.1111/j.1469-7998.1995.tb05128.x

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0280327

https://publikace.nm.cz/en/file/5e49279b626bef9886ade2ab551f8e53/18267/005-012_Canady.pdf

https://www.tandfonline.com/doi/abs/10.1080/21658005.2015.1044164

Posted by milewski 11 months ago

A reminder of the distribution ranges of the various spp. of Lycalopex:

https://upload.wikimedia.org/wikipedia/commons/5/59/Lycalopex_range.png

Posted by milewski 11 months ago

I hadn't thought of the anatomy of Aenocyon in my previous comment. It's possible what you noted might have been an inhibitor of hybridisation, and certainly, it's an important detail that I missed out on.

Posted by paradoxornithidae 11 months ago

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