Record Size Jaguar & Lion Skull

Best thing to do would be to look at Boone and Crockett records. Maybe also look at SCI records to see what they have listed as record size skulls. Not all record animals are in hunter logs. Some really big skulls were collected by museum collectors and have never been recorded as a hunting record.

I've been close to live jaguars. They will easily dwarf a leopard.

 

I've seen a couple of lion skulls that scored just shy of 28" (16 3/4" long and 11.5" wide for one of these - I sell a cast of it on Ebay : https://www.ebay.com/itm/262733812926). As I recall from looking at SCI records the very biggest were about an inch larger overall than this one. As for a jaguar, you'd have to look that one up. I have a cast for sale from a large male but not as big as the one you are referring to.
On a side note, what I find interesting is it seems that the largest tiger skulls (though of course big game records are scant because they have been protected for a long time) pale in comparison to the largest lions. I put a Bone Clones Siberian tiger cast next to my "Lionzilla" and it was rather unimpressive. Supposedly tigers (the Siberian variety anyway) are the biggest cats alive but they seem to have finer and smaller skulls. From my limited experience handling the real thing, lion and jaguar skulls are heavy and robust while tiger and leopard are "finer" and lighter weight.

 

That's really impressive. Are there any pictures of these particular big cat skulls?