Sunday, July 3, 2022

Fossil Felids of the National Park Service

For this year's annual focus on a fossil group in National Park System units, I am going to pay my Internet cat tax and present a quick look at the fossil felids of the parks. If you're not familiar with the history of Felidae, it may come as a surprise that cats are a relatively recent innovation. They have only a few tens of millions of years under their collective belts, and didn't arrive in North America until Pseudaelurus in the early Miocene. (Note: barbourofelids and nimravids may give off saber-toothed cat vibes, but they aren't Felidae.)

It turns out that there are 24 NPS units with cat body or trace fossils. All of the records, unsurprisingly, are early Miocene in age or younger. The great majority are Quaternary (concerning the question of when to cut off the paleontological record, caves don't discriminate if you happen to be 11,000 years old rather than 12,000 years old, and neither do we): only seven of the 24 park units have pre-Q cats. These are Big Bend National Park, Death Valley NP, Hagerman Fossil Beds National Monument, John Day Fossil Beds NM, Lake Mead National Recreation Area, Mojave National Preserve, and Niobrara National Scenic River.

These maps are so much easier to make now that I have one file with all of the parks as points, and I can just turn them on and off. 1. John Day Fossil Beds National Monument; 2. Oregon Caves NM; 3. Lava Beds NM; 4. Hagerman Fossil Beds NM; 5. Yellowstone National Park; 6. Great Basin NP; 7. Death Valley NP; 8. Tule Springs Fossil Beds NM; 9. Lake Mead National Recreation Area; 10. Mojave National Preserve; 11. Joshua Tree NP; 12. Grand Canyon NP; 13. Chaco Culture National Historical Park; 14. White Sands NP; 15. Carlsbad Caverns NP; 16. Guadalupe Mountains NP; 17. Big Bend NP; 18. Amistad NRA; 19. Waco Mammoth NM; 20. Niobrara National Scenic River; 21. Ozark National Scenic Riverways; 22. Chickamauga & Chattanooga National Military Park; 23. Potomac Heritage National Scenic Trail; 24. Valley Forge NHP.

Geographically the sites are concentrated in the southwestern US; in fact, 15 of the sites are in Arizona, California, Nevada, New Mexico, or Texas. This seems to say something about cat biogeography, given these are mostly Quaternary sites and the NPS has a pretty good Quaternary record in terms of geographic spread. I wouldn't base a thesis on it or anything, though.

It's not stated on the map, but the Quaternary record is heavy on caves; a dozen of the records are from caves or rock shelters. These included significant records at Carlsbad Caverns NP, Grand Canyon NP, Guadalupe Mountains NP, Potomac Heritage NST (Cumberland Bone Cave), and Valley Forge NHP (Port Kennedy Bone Cave).

Most of the records are body fossils, but at least three have cat trace fossils: tracks at Death Valley NP and White Sands NP, and tracks and cave scratches at Chickamauga & Chattanooga NMP. One of these sites has yielded a track type specimen, Felipeda scrivneri Sarjeant et al. (2002) from Death Valley NP. There are also eight fossil felid species named from body fossils discovered within or potentially within NPS areas (all named before the units were established):

  • Felis lacustris Gazin (1933) from Hagerman (now Puma lacustris)
  • Machairodus? hesperus Gazin (1933) from Hagerman (now Megantereon hesperus)
  • Felis augustus Leidy (1872) possibly from Niobrara (now Panthera onca [augusta], and Pleistocene instead of Miocene in age)
  • Felis (Pseudaelurus) intrepidus Leidy (1858) possibly from Niobrara (now Pseudaelurus intrepidus)
  • Crocuta inexpectata Cope (1895) from Valley Forge (now Miracinonyx inexpectatus) 
  • Lynx calcaratus Cope (1899) from Valley Forge (now considered a synonym of Lynx rufus)
  • Smilodon gracilis Cope (1880) from Valley Forge
  • Uncia mercerii Cope (1895) from Valley Forge (now considered a synonym of Smilodon gracilis)

Attaining consensus on cat taxonomy and nomenclature can be like, well, herding cats. It doesn't help that it can be difficult to tell cats apart; see a record of "Panthera onca" at Carlsbad Caverns NP becoming Panthera atrox (Kottkamp et al. 2022), and "Puma concolor" fossils at Grand Canyon NP becoming Miracinonyx trumani (Hodnett et al. 2022; take the skull for a spin here). Nevertheless, the Quaternary sample can be divided among seven species or species groups. Three are extinct:

  • American cheetah (Miracinonyx inexpectatus and M. trumani): found at Carlsbad, Grand Canyon, Potomac Heritage, and Valley Forge
  • American lion (Panthera atrox): found at Carlsbad, Potomac Heritage, and Tule Springs
  • Saber-toothed cats (Smilodon spp.): found at Potomac Heritage, Tule Springs, Valley Forge, and Waco Mammoth

Two are still around but not this far north:

  • Jaguar (Panthera onca): found at Lava Beds, Oregon Caves, Ozark, Potomac Heritage, and Valley Forge (these are all pretty far north for something we associate with tropical jungles!)
  • Jaguarundi (Herpailurus yagouaroundi): found at Valley Forge

Finally, two are still found in the United States:

  • Bobcat (Lynx rufus, with allowance for Lynx sp.): Amistad, Carlsbad Caverns, Chaco Culture*, Great Basin*, Grand Canyon, Guadalupe Mountains, Joshua Tree*, Lava Beds, Tule Springs, Valley Forge, and Yellowstone* (*=Holocene only)
  • Cougar/mountain lion/puma (Puma concolor): Carlsbad Caverns, Chaco Culture*, Guadalupe Mountains, and Tule Springs

The most species-rich sites are:

  • Carlsbad Caverns NP (American cheetah, American lion, bobcat, cougar)
  • Hagerman Fossil Beds NM (American cheetah, Homotherium sp. [a saber-toothed cat], Lynx rexroadensis, Megantereon hesperus [or cultridens; another saber-toothed cat], Puma lacustris)
  • Tule Springs Fossil Beds NM (American lion, bobcat, cougar, saber-toothed cat)
  • Valley Forge NHP (American cheetah, bobcat, jaguar, jaguarundi, saber-toothed cat)

Of these four, the Hagerman assemblage is Pliocene, the Valley Forge assemblage is middle Pleistocene, and the other two are late Pleistocene. In the Pleistocene, at least, a robust cat assemblage may include a big lion-type cat, a saber-toothed cat, a smaller big cat (but apparently not cougars and jaguars at the same place), and a bobcat-sized cat.

Felids are relatively uncommon compared to the other big terrestrial carnivorans. Fossil dogs and bears are more widely distributed in NPS units than cats. Furthermore, all but one NPS assemblage that has cats also has dogs, bears, or both (the exception being the Pliocene tracks of Death Valley NP). These groups, though, are for another time...

References

Cope, E. D. 1880. On the extinct cats of America. American Naturalist 14(12):833–858.

Cope, E. D. 1895. The fossil Vertebrata from the fissure at Port Kennedy. Proceedings of the Academy of Natural Sciences of Philadelphia 47:446–450.

Cope, E. D. 1899. Vertebrate remains from Port Kennedy bone deposit. Journal of the Academy of Natural Sciences of Philadelphia, 2nd series, 11(3):193–286.

Gazin, C. L. 1933. New felids from the upper Pliocene of Idaho. Journal of Mammalogy 14:251–356.

Hodnett, J. P., R. White, M. Carpenter, J. Mead, and V. L. Santucci. 2022. Miracinonyx trumani (Carnivora; Felidae) from the Rancholabrean of the Grand Canyon, Arizona and its implications on the ecology of the “American cheetah.” New Mexico Museum of Natural History Bulletin 88:157–186.

Kottkamp, S., V. L. Santucci, J. S. Tweet, R. D. Horrocks, and G. S. Morgan. 2022. Pleistocene vertebrates from Carlsbad Caverns National Park, New Mexico. New Mexico Museum of Natural History and Science Bulletin 88:267–290.

Leidy, J. 1858. Notice of remains of extinct Vertebrata, from the valley of the Niobrara River, collected during the exploring expedition of 1857, in Nebraska, under the command of Lieut. G. K. Warren, U.S. Top. Eng., by Dr. F. V. Hayden, Geologist to the expedition. Proceedings of the Academy of Natural Sciences of Philadelphia 10:20–29.

Leidy, J. 1872. Remarks on some extinct vertebrates. Proceedings of the Academy of Natural Sciences of Philadelphia 24:38–40.

Sarjeant, W. A. S., R. E. Reynolds, and M. M. Kissell-Jones. 2002. Fossil creodont and carnivore footprints from California, Nevada, and Wyoming. Pages 37–50 in R. E. Reynolds, editor. Between the Basins: Exploring the western Mojave and southern Basin and Range Province. California State University, Fullerton, California.

Sunday, June 26, 2022

The doldrums

There's been a distinct lack of dinosaurian content around here for the past few months. To be honest, this is partially on my end: my own attention and energy have been elsewhere, and I haven't been all that interested in what has been coming down the pipe (I don't care if spinosaurs fished, hunted, scavenged, browsed, or got take-out). However, there is something external going on as well. With about half of the year in the books, I think it's reasonable to guess that 2022 is not going to be remembered as a banner year in the field of dinosaur paleontology. This is a predictable result of the COVID-19 pandemic: you don't just find a couple of bones in the rock and name them then and there. (Well, you *can*, but it generally doesn't go over well. Don't you at least want to prep the bones first?) Between excavation, preparation, comparative study, writing, revising, reviewing, and publishing, description of a fossil takes years. What happens when travel is greatly curtailed and museums close their doors? You've cut off those first three parts. Sure, maybe you have time to write now, but you can't participate in expeditions and excavations, you can't prepare fossils, and you can't go to other institutions to look at their specimens. The slowdown wasn't immediately evident in the literature in 2020 because there were still plenty of papers in the pipeline. With that in mind, there was still a pretty decent flow through 2021.

Then things tightened up. Looking at one measurement of activity, in 2022 we've gone through three stretches of a month or more without a new genus or species: from late December 2021 to early February 2022, mid-March to late April, and early May to the present. We're currently in the longest gap between new taxa since whatever happened (or didn't happen) between late November 2016 and early February 2017. In addition, many of the species that have been named are not known from especially complete specimens, to put it politely. I don't know about you, but I've gotten the impression that there's been some clearing out of small projects (which would make sense under pandemic conditions). This slowdown would reflect the challenges of working on research projects in 2020–2021, and it would be safe to suspect that we are in for at least a few more slow months (with the opportunity for global political and economic instability to wreak their own impacts following).

Sunday, June 12, 2022

Fusulinids: Jumbo Forams

Foraminifera are among the most abundant and best known kinds of microfossils (and they aren't exactly confined to the past, either). While it's true that many aren't microscopically microscopic, they're still smaller than is comfortable for practically any human being to study without some kind of magnification at hand. Without such, you'd be stuck squinting at sand-grain-sized things and making such helpful observations as "okay, this one looks like a stack of spheres, and this one is coiled up, and this one is... no, wait, that's an itty-bitty fish vertebra or something." And then there are some that don't require quite as much eye strain to spot.

Like these: every grain-looking thing is a foram.

Among these giant microfossils are the fusulinids (or "fusies" if you're lazy like me), the kings of the realm of single-celled organisms during the late Paleozoic. If you can see something the size of a rice grain or a grass seed, you can see a fusulinid. In fact, the comparison will give you the idea of what to look for: fusulinids tend to look like fat, whitish seeds. The Latin word "fusus" means "spindle-shaped", or "something that's long, widest in the middle, and tapering at the ends". There's your fusulinid.

And there's another, and another... These are getting to around 3 mm long, or a bit more than a tenth of an inch. (Note also what looks to be a sliver of a trilobite pygidium near the center.)

During their heyday, fusulinids could be so abundant that their tests (shells, basically) could more or less make up sediment beds. The resulting rocks are a bit monotonously fossiliferous, as fusulinids tended to look the same on the outside. The interior architecture of chambers is how different species are distinguished, so even though you can see them without needing a microscope, you're going to need one to tell them apart. (Plus the grinding and polishing and all that jazz.) "Why bother?", you may ask. Well, it turns out that the geologically rapid turnover of fusulinid species makes them great biostratigraphic indicators in some places where people are keenly interested in subterranean resources (like the Permian oil fields of Oklahoma and Texas). Know the fusulinids, know the rock; know the rock, know the resources.

Zooming down to an even closer look, we can see that many of the fusulinids have a "perforate" appearance, which is the result of weathering exposing some of the internal chambers. Although most of the forams are seen lengthwise, there are some cross-sections scattered throughout, showing rings of chambers.

The particular examples in these photos come not from in situ outcrops, but building stone. The rock is Cottonwood Limestone used in historic structures in Kansas, and although there are other fossils, the fusulinids are by far the most abundant. The Cottonwood is early Permian in age (Wolfcampian stage in the grand old North American series), so at this point the fusulinids had a few tens of millions of years left to flourish before bowing out at the end of the Permian. According to my old copy of "Invertebrate Fossils" by Moore, Lalicker, and Fischer (1952), this would most likely represent the Pseudoschwagerina zone.

The stairs are made of forams! (No, it doesn't have the same ring as "The floor is lava!", but you *are* walking on the bodies of millions of fossilized amoeba things...)

Sunday, May 29, 2022

Recent Work from the National Park Service Paleontology Program

My day job is with the Paleontology Program of the National Park Service, and I thought you might like to see some of the work we've put out over the past few months. First up is the Spring 2022 issue of the Park Paleontology newsletter. For this issue, we have articles on:

Next, a couple of articles have just come out in the latest volume of the New Mexico Museum of Natural History and Science Bulletin series, both focused on Quaternary cave paleontology of specified parks in the southwest. Hodnett et al. (2022) describes previously overlooked bones from Grand Canyon National Park as specimens of the "American cheetah" Miracinonyx trumani. Meanwhile, drawing on the Carlsbad Caverns National Park paleontological inventory published a few years ago, Kottkamp et al. (2022) discusses the Pleistocene vertebrate record of the park's various caves.

Finally, public versions of our four latest park-specific paleontological inventory reports are also available to view and download. For just four parks, they feature a wide range of types of fossils, geology, and geography. They are:

References

Hodnett, J. P., R. White, M. Carpenter, J. Mead, and V. L. Santucci. 2022. Miracinonyx trumani (Carnivora; Felidae) from the Rancholabrean of the Grand Canyon, Arizona and its implications on the ecology of the “American cheetah.” New Mexico Museum of Natural History Bulletin 88:157–186.

Kottkamp, S., V. L. Santucci, J. S. Tweet, R. D. Horrocks, and G. S. Morgan. 2022. Pleistocene vertebrates from Carlsbad Caverns National Park, New Mexico. New Mexico Museum of Natural History and Science Bulletin 88:267–290.

Sunday, May 15, 2022

Rockfall

One of the characteristic aspects of the Mifflin Member of the Platteville Formation is its habit of planar jointing. The faces of outcrops often look like someone took a rock saw to them. Nor are they necessarily single flat planes; sometimes joints intersect to form sharp angles. The heavy thunderstorms the previous week inspired a large chunk of Mifflin outcrop to collapse along intersecting joints.

Tumbled down

The joint planes did not form overnight, which can be seen by the amount of roots and soil in the new outcrop faces. There were some pretty big roots in there as well, but whatever tree(s) had once produced them is long gone.

A view into the wedge more or less along one of the two joints.

This particular rockfall was about as polite as possible, occurring not at the top of a stereotypical 30-foot bluff but from a much lower bluff, adjacent to a bike path. The orientation of the wedged stack shows that it toppled out of its former position. The top of the stack is therefore farthest from the bluff. Perhaps it failed at the base first, due to poor support from the Pecatonica, then flopped over.

History going from left to right

Saturday, April 30, 2022

Synchronicity of Large Crinoids

I was recently out of town for work, and one of the things I saw was Middle Pennsylvanian-age building stone with stem segments from large crinoids:

Big ol' crinoids

It's like bony fingers strewn on the ground

You'd think with all this stem, there'd be a calyx somewhere, but no dice

At a shade over 1 cm (about 0.4 in) in diameter, the columnals are quite a bit bigger than garden-variety columnals, but still are well shy of world champ columnals, which reportedly exceed 2.5 cm (1 in); certainly much bigger than anything in Minnesota, right?

Yes! Time for the ironic photo!

Only yesterday, less than a week after returning from the above trip, I was visiting a couple of Decorah Shale sites and came across the above specimen. I happened to be caught short of a traditional scale bar, so you will have to take my word that the fingernail of the above finger is 1.1 cm (0.43 in) across at its widest point. Therefore, that columnal is 1.5 cm (0.59 in) across, which is pretty darn big for anything in the Decorah except for certain trilobites. In fact, it made me wonder if the stone might be a ringer transported from another formation, by glacier, river, or what-have-you. (Not impossible at all; here's a neat report on all kinds of exotic rocks and fossils found in Mississippi gravel, including Lake Superior agates and Sioux Quartzite; closer to home, a piece of an Upper Cretaceous ammonite was once found at the Brickyard, as related in Cobban and Merewether 1983:19.) However, the chunk shows no evidence of transport, and lithologically it looks the same as any piece of thin limestone eroded out of the Decorah. Were it not for the great honking columnal, I wouldn't have thought twice about its legitimacy. (I wouldn't even have thought once!) My guess is that this particular specimen originated from higher in the formation than the stuff I usually see, or that great honking crinoids were a very minor part of the Decorah fauna and this just happens to be my first encounter.

References

Cobban, W. A., and E. A. Merewether. 1983. Stratigraphy and paleontology of mid-Cretaceous rocks in Minnesota and contiguous areas. U.S. Geological Survey, Washington, D.C. Professional Paper 1253.

Sunday, April 10, 2022

Mitchell Caverns

Back in the fall of 2021, I made a work visit to Mojave National Preserve, located logically enough within the Mojave Desert of southern California. While there, I had the opportunity to tour Mitchell Caverns. Mitchell Caverns is in the unusual position of being part of a state land parcel (Mitchell Caverns Natural Preserve or State Natural Preserve, depending on the source), entirely surrounded by another parcel of state land (Providence Mountains State Recreation Area), which is itself surrounded by a National Park Service unit (Mojave National Preserve). For good measure, the cave system is also a National Natural Landmark. It's parks all the way down in the Providence Mountains. (To be fair, the natural preserve designation is kind of a map artifact; it's not really distinct from the state recreation area.)