Moumantai ~

In the early 20th century, instruments were invented that enabled geologists to measure the weak magnetic field produced by rocks. This led to an amazing discovery. Not all rocks had the same orientation of the dipole.

Why is that such a big deal? Let's imagine for a second that we are on the equator in South America where the inclination and declination should be 0 degrees. If you measure the weak magnetic field in a 100 million year old rock, you'll find that it doesn't point to the present day north pole. This is because it's declination is different than the declination the compass would normally display at that spot. We call this paleomagnetism.

So, why don't paleomagnetic dipoles point to today's north pole? That was a tough question to answer for a long time. Most geologists at the time still believed that the continents were in a fixed position so they concluded that the magnetic poles had moved over time. With this concept in mind, geologists set out to measure the "paleopoles". What they found surprised them.

They measured the paleomagnetism in a succession of rocks of different ages in the same general location on a continent. Seems simple enough...until they put multiple continents apparent polar-wander paths together.

If the pole was moving, all the polar-wander paths should match. Clearly, they do not. How is that possible? Unless Wegener was correct and the continents moved not the poles.

i need to prove that i'm not insane

All of the Prehistoric Pride guys in one collective post to celebrate pride month. Choose your fighter and have an awesome time :D

Majestic

Brachycephaly is a problem.

Schlueter et al (2009) categorized brachycephalic head shapes into four categories randing from mild to severe.

Moderate brachycephaly is where we begin to really see problems and profound or severe brachycephalic cats are going to have a real issue.

The British Shorthair (left) is a breed where mild brachycephaly is part of the standard compared to an Exotic Shorthair (right) where profound - severe brachycephaly is desireable.

On the left with have a British Shorthair, in the center an Exotic Shorthair and on the right a Persian.

One of the problems we see with brachycephalic breeds is stenotic nares, which are narrow nostrils. You can’t even make out the nares on the Persian shown above and, as one may expect, this affects how much air they move through them.

We can see similar obstructive effects in cats with nasopharyngeal polyps, masses or reconstruction due to scarring from chronic rhinosinusitis problems.

Due to their inability to breath normally through their nose these cats tend to be heat and exercise intolerant and can run into trouble more quickly during high stress events.

Stenotic nares can be surgically corrected but I don’t think this is as common in cats as it is in dogs, at least I haven’t encountered many cats who’ve undergone the procedure. I don’t know if it’s not as necessary, if cats don’t respond as well or if cat owners are less likely to seek treatment.

Or maybe it is as common and my lack of experience is the outlier.

Brachycephaly is also associated with malocclusion and dental disease, chronic epiphora, facial dermatitis related to the chronic tearing and ocular issues such as conreal sequestrum or entropion related to the protruding eye structure.

I know globe proptopsis is a problem in some brachycephalic dog breeds like pugs but I haven’t heard of this specifically happening in brachycephalic cat breeds.

Exotics and Persians are obviously the worst when it comes to brachycephaly in cats but the Bombay and (American) Burmese are also offenders.

There are other breeds which don’t call for a brachycephalic head shape (or even default it) or call for only a mild version but certain breeders are selecting for extreme typeing anyways because even though their cats might not win any shows they can sell them as designer variants for more.

On the left we have a Sphynx and in the right we have a Devon Rex both with an extreme head type contradictory to the breed standard.