This New Zealand YouTuber recently uncovered a massive 12-million-year-old crab fossil sealed in rock.

Mamlambo Fossils filmed a timelapse as he intricately removed the rock enclosing the fossil.

"The species is a Tumidocarcinus giganteus from the mid-Miocene, around 12-million-years-ago," he told Newsflare.

"The prep took 208 hours and the processing of the 1200GB of 4K footage took another 20 hours and I still had to edit the video itself. All in, I think I have spent 250 hours on this project!" he added.

"The final weight of the crab is 7.3kg, more than 16kg of rock was removed chip by tiny chip," he concluded.

It's been almost two years since I found the 50lbs (23.7kg) fossil crab concretion and I was starting to feel confident in my crab prepping skills, so I decided to make a start on the best fossil crab I have found so far.

It started off badly as I prepped the bottom of the crab first and had to start over again on the other side of the concretion. I was using a combination of an angle grinder and a chisel to remove the bulk of the rock but it was very slow going. Luckily, my large air scribe, the Motovator, arrived and made a HUGE difference. It removes about ten times as much rock as my other scribe does in the same time.

The species is a Tumidocarcinus giganteus from the mid-Miocene, around 12-million-years-ago.

People always ask what the value of this crab would be and the short answer is that the value is the labour you put in. Unprepped crabs aren't worth much - 95% of the value is in the hours you spend prepping it with specialised equipment.

I use a variety of air scribes on the fossil crab. The Motovator for rough work, a middle-of-the-range scribe for 60% of the work and a very fine one for cleaning up the joints and other delicate areas.

The prep took 208 hours and the processing of the 1200GB of 4K footage took another 20 hours and I still had to edit the video itself. All in, I think I have spent 250 hours on this project!

The final weight of the crab is 7.3kg, more than 16kg of rock was removed chip by tiny chip.

Parts of the video:
00:00 - 00:18 Finding the fossil crab in a concretion (hardened siltstone) - identified by the leg rings visible on either side of the rock
00:19 - 00:29 Using an angle grinder to remove excess rock
00:29 - 00:44 Hand chisel to remove more of the rock, it's very slow and painful so I had to make a plan
00:44 - 00:59 My new air scribe, the Motovator arrives to replace the hand chisel
01:00 - 01:08 Removing excess rock with the Motovator
01:09 - 01:33 Crab carapace starts showing
01:34 - 01:40 Adding paraloid (B72) to consolidate the carapace and stop it from flaking off with the vibrations caused by the air scribe
01:40 - 01:54 Removing more rock from the carapace with the smaller air scribe
01:55 - 02:20 Crab shoulder starts appearing and the I move on to the claw
02:21 - 02:28 A crack started forming so I took a chance and knocked a big section of rock off, it worked well and saved me 4 hours of work.
02:46 The left claw starts showing
04:10 Legs start being revealed
05:25 "Landscaping" starts - this is where the air scribe marks are smoothed to be more aesthetically pleasing
05:47 Previous crab is shown for size comparison
06:28 The monster crab joins the rest of my crab collection - dwarfing the other crabs