Pennsylvania Earth Sciences Association - PESA club and Mineralfest

03/09/2026

'The Bone Wars' be be refilmed for YouTube and I hope to have it up on the channel this week - we're over 500 subscribers now and thanks to you all!

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03/09/2026

Getting back to regular videos with an updated version of one on a seminal topic in paleontology - the decades long 'fossil feud' between the two top names of the times; Edward Drinker Cope and Othniel Charles Marsh. Their infighting and battles galore revolutionized the science...but how did things happen?

03/08/2026

https://sacredearthminerals.com/freshwater-mosasaurs/?fbclid=IwY2xjawQZqXJleHRuA2FlbQIxMQBzcnRjBmFwcF9pZBAyMjIwMzkxNzg4MjAwODkyAAEePUkySN-4Jotze-sU3QHVtdKpFEO3NlZk7SLech301ZhPt1cqTIbCyZJ1YNo_aem_ntvBxM6VMt8EyaYXUKQltQ

Freshwater mosasaurs lived in Late Cretaceous rivers. Discover how isotope analysis from Hell Creek reshaped our understanding of mosasaur habitats.

03/08/2026

Crystal Cave is back! We’re eager for you to explore the cave and marvel at its wonders.
We reopen this Sunday, March 1st from 9am – 5pm!! We hope to see you there!

03/08/2026

Grab your helmet and gear up for the weekend, because it’s Fossil Friday! Dinosaur lovers might recognize Pachycephalosaurus, an herbivore that lived during the Cretaceous some 66 million years ago. It was once theorized that this critter, like modern bighorn sheep, used its distinctive skull as a battering ram. However, more recent studies have challenged this idea.

The horns of bighorn sheep create a broad, flat area on the front of the skull which is well-suited for head-to-head combat. But the rounded skull of Pachycephalosaurus would mean that two sparring individuals’ heads would have essentially glanced off each other. The animals might also have been injured if their heads twisted to the side upon impact. If Pachycephalosaurus did fight with its head, it probably knocked its opponents’ sides, like modern day bison. This dinosaur may have also used its unique dome to recognize members of the same species or compete for mates.

Photo: D. Finnin/AMNH

03/06/2026

Right on the heels of sharing the Mineralfest ad here's another wee reminder - please do not fall for scam posts for us or any other mineral show! Sadly these posts are getting very common; with scammers soliciting for tables in the discussion pages of events or other places. If you would like to vend at any show please contact the sponsoring club directly and pay no mind so so called 'Event Planners.' Fortunately this one got flagged by my discussion feed bots and so their post is up for a public shaming.

A very big giveaway that this is a fake post...this may seem obvious to some but as this has come up in PMs I will address it. We aren't a craft show! Crafts are great, sure, but if you see someone casting a wide net for vendors outside of the main vibe of a show they're trying to see how many kinds of people they can nab. So if you're a hopeful dealer - don't fall for any scam posts this year!

03/06/2026

Shattuckite with Malachite and Quartz