Friday Headlines: 4-12-13

Friday Headlines, April 12, 2013

THE LATEST IN THE GEOSCIENCES

 

KENNECOTT TO KEEP REFINING AFTER HUGE SLIDE IN UTAH COPPER MINE

I grew up in Salt Lake City. (I know what you’re thinking. The answer is no.) Kennecott Copper was this massive open-pit mine up in the mountains that sometimes we’d get field trips to. Over the years, of course, it’s gotten deeper and deeper.

A photo into Bingham Pit, where Kennecott gets it’s copper ore. Those vehicles in the bottom are actually massive dump trucks two stories tall!

The walls of the pit are very steep, and it was bound to happen. Gravity always wins in the end. There was a land slide.

The aftermath of the slide.

Impressive.

 

FISH FOSSIL SHOWS WHY HUMANS HAVE TWO ARMS, LEGS

I think this title is a bit deceptive. This fish does lend some insight into why it is that humans have two arms and two legs, but it’s rather ego-centric to assume that this find applies only to humans.

This is actually more fundamental than this. Humans, as well as nearly all jawed vertebrates (that is animals that have backbones and jaws) have paired appendages. Two front legs, two back legs. Two wings, two sets of talons. And two front (pectoral) fins and two back (pelvic) fins.  What we’re still trying to learn is when did these paired limbs evolve?

We’ve rather selfishly thought (and it’s been borne out a bit by the fossil record) that paired limbs are an exclusive trait within the jawed vertebrates. In other words, if it has paired limbs, it has a jaw. This new species of fish clearly has paired limbs. But it lacks a jaw.

Fossil of Euphanerops showing the paired anal fins. (Photo by Robert Sansom)

Euphanerops is a new species of ostracoderm (‘bony skin’) fish that lived about 370 million years ago. This is about the time when fishes were starting to develop jaws (which is an interesting story). Ostracoderms lack jaws.

Some ostracoderms

There are some jawless fishes still alive today, particularly hagfish and lampreys. They’re ugly critters, not nearly as stylish as the ancient, armored ostracoderms.

Euphanerops, unlike any known jawless fish including other ostracoderms, clearly has paired limbs. The argument here is not necessarily that paired limbs appeared in fishes before jaws, but that paired limbs may have evolved multiple times in several unrelated groups as an evolutionary experiment.

2 Comments

  1. Dave H says:

    I remember seeing that mine from the air as I flew into SLC in the early 80s. It was impressive even then. I didn’t realize they were still working it. I thought I’d heard it was closed.

    Do any neat fossils come out of that mine?

    Like

    1. Penny says:

      So far as I know, there are no fossils collected from that mine. Ore deposits like that tend to preclude fossil preservation.

      Like

Leave a Comment

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s