#mammoth cave

[where-is-the-sam-standee]

Mammoth Cave!

The Sam standee is at Mammoth Cave National Park in Kentucky!

[mitesworld]

Green river baby

[uxbridge]

Hydrangeas at Sand Cave, Mammoth Cave National Park, Kentucky

[randomanimaloftheday]

Day 331#: Macadens olsoni

Today's animal of the day is Macadens olsoni!

Image credit: Benji Paysnoe

This species of extinct cartilaginous fish lived during the Early Carboniferous period in what is now Kentucky. Specifically, its remains were found in Mammoth Cave, which encompasses more than 426 miles and is the longest cave system in the world! It's also full of fossils, mostly of ancient sea creatures like crinoids, brachiopods, and many species of prehistoric fish, like Macadens. Ironically, there aren't any mammoth remains in this cave, and the name mostly just refers to how enormous the cave system is.

Photo credit: National Parks Service

Macadens was discovered in 2020 during an expedition by the National Park Service called the Paleontological Resource Inventory, which sought to document as many fossils within Mammoth Cave as possible. It was given the genus name Macadens, which is an abbreviation for "Mammoth Cave Denizen", while its species name honors Rickard Olson, who is a now-retired scientist who used to work at Mammoth Cave National Park. Even though it was discovered in 2020, it took some time before the team of paleontologists working on the fossil made the news available to the public, which is normal in paleontology since you want to know what exactly you've found before telling the rest of the world about it. Macadens was finally revealed to the public on July 24, 2025, during Shark Week.

A modern-day Rabbitfish, which is a type of Chimaera and a possible relative of Macadens (photo credit: Vebjam Karlsen)

The timing of this was great for spreading the news of Macadens' discovery, but it did lead to many news articles labeling it as a "new species of prehistoric shark". Currently, paleontologists aren't 100% sure what type of cartilaginous fish Macadens is. The leading theory is that it is a member of Holocephali, which includes modern-day Chimaera, which are sometimes called ghost sharks, but aren't actually sharks. That's not to say that Macadens was a Chimaera; likely, it belonged to its own closely related group, but until more material is found, we can't be totally sure.

Macadens tooth (photo credit: National Parks Service)

In life, Macadens was a relatively small fish, only around 12 inches long, and lived in a shallow warm-water seaway, called the Mississippian Seaway, which covered parts of what is now North America, Europe, and North Africa. Keep in mind that during this time, all the continents hadn't broken up yet and were still joined together to form the supercontinent of Pangaea. Based on the type of limestone sediment in which Macadens was found, paleontologists know that it would have lived in a relatively shallow area that would have been filled with corals, crinoids, and other marine invertebrates. The teeth of Macadens were blunt yet robust, which suggests that they likely used them to crush open the hard exoskeletons of their prey. Because of this, paleontologists suspect that Macadens would've spent much of its time searching the seafloor around these reefs for mollusks and marine worms buried in the substrate.

[dromaeo-sauridae]

big cave post

you like caves? no? im showing you anyway. you hear cave and probably think of like, a video game cave. maybe a minecraft cave with axolotls? while i have my gripes with axolotls in caves, this is about the caves themselves. so here, lets get started:

number 1, lod cave in thailand. now, i could do a whole posts about JUST caves in thailand, but here's your first taste of caves from this area. this is a karst cave, formed by water trickling through soluble rock like limestone. it's what most of the caves on this list are going to be. it's one of the most common types of caves. if you've been inside a cave, it was probably a karst. very cool! i particularly enjoy the man shaped stalagmite in the middle (joke, thats just a real guy)

number 2, ellison's cave in georgia, usa. featuring a drop over a thousand feet deep, this one is pretty high on my bucket list. this is what's called a chute, formed by waterfalls cascading downwards. not recommended for people with a fear of heights! if you watch jacon geller, youve probably heard of this type of formation when he talked about krubera (not on this list, sadly)

number 3, mammoth cave in kentucky, usa. one i've been to! mammoth is the longest cave system in the ENTIRE world, that we know of. another one the jacob geller fans are familiar with. i would love to go back someday, pictures dont convey the magnitude of this place. they also used to host church services in here. well worth the visit

number 4, han son doong in vietnam. the LARGEST cave in the world! wait, didnt i already list that? nope, while mammoth is the longest and is massive in its own right, son doong trumps it by having a ceiling 660 feet (200 meters) high. it has stalagmites the size of skyscrapers. its one of the many caves in southeast asia to have its own rainforest system. a bit of a hike to get there, but another i desperately want to visit someday.

number 5, fingal's cave in scotland. though not record setting, its one youve probably seen before. or, maybe my perspective has been skewed as someone who looks at a LOT of caves. ive seen this exact picture more times than i can count. its a sea cave formed from our good friend columnar basalt. upon further research, apparently its also known for its natural acoustics. the more you know!

number 6, grotta azurra in capri. that photo isnt edited! only accessible by boat (and laying flat on your back to get through the entrance) this place looks ridiculously magical. i dont really have much to say about this one, i just think its really cool.

number 7, domica cave in slovakia. this one was brought to my attention by an anonymous asker (if youre still here hi) and i am in love with it. just an absolutely gorgeous cave with some of the most beautiful formations ive ever seen. just look at it! augh! the tiered pools arent something ive seen in any of the caves ive been to and theyre captivating. i love caves.

number 8, ending it off with a bang. here's the gloup.

[ukdamo]

Notes on the Below

Ada Limón

—For Mammoth Cave National Park

Humongous cavern, tell me, wet limestone, sandstone caprock, bat-wing, sightless translucent cave shrimp,

this endless plummet into more of the unknown, how one keeps secrets for so long.

All my life, I’ve lived above the ground, car wheels over paved roads, roots breaking through concrete, and still I’ve not understood the reel of this life’s purpose.

Not so much living, but a hovering without sense.

What’s it like to be always night? No moon, but a few lit up circles at your many openings. Endless dark, still time must enter you. Like a train, like a green river?

Tell me what it is to be the thing rooted in shadow. To be the thing not touched by light (no that’s not it) to not even need the light? I envy; I envy that.

Desire is a tricky thing, the boiling of the body’s wants, more praise, more hands holding the knives away.

I’ve been the one who has craved and craved until I could not see beyond my own greed. There’s a whole nation of us.

To forgive myself, I point to the earth as witness.

To you, your Frozen Niagara, your Fat Man’s Misery, you with your 400 miles of interlocking caves that lead only to more of you, tell me,

what it is to be quiet, and yet still breathing. Ruler of the Underlying, let me

speak to both the dead and the living as you do. Speak to the ruined earth, the stalactites, the eastern small-footed bat,

to honor this: the length of days. To speak to the core that creates and swallows, to speak not always to what’s shouting, but to what’s underneath asking for nothing.

I am at the mouth of the cave. I am willing to crawl.

[victusinveritas]

[jesslovesboats]

SPEAKING OF CAVES, we went to Mammoth Cave this weekend and had a great time! But first, on the way there, we stopped to visit cultural icons Cocaine Bear and the Hell is Real sign.

The cave was incredibly cool! We didn't get to do as much hiking outside as we hoped because it was approximately one billion degrees outside, but the inside of the cave is 54 degrees year round and it felt amazing

My favorite part of this trip was learning about Floyd Collins and seeing Sand Cave, his family home, and Crystal Cave. This was a ranger-led tour but it was completely free because it doesn't go inside any caves. I've decided that park rangers are pretty much my favorite humans- they're incredibly smart and resourceful, and they genuinely love sharing their knowledge!

This was my husband's birthday trip and it kind of came together at the last minute, but it ended up being a great weekend getaway. 10/10 highly recommended, but if you go when the heat index isn't over 100F, you'll be able to do a lot more outside.