A case of wrong birds from what is labeled on the bin at TSC. Chicks get mixed up. Tetra Poultry Genetics company, the original makers of the Tint, just one of their layer models, is a light weight laying hybrid.
What you have is undoubtedly a commercial broiler, commonly called the CX or CornishCross, etc. It is bred to mature quickly and butchered at 8-9 weeks. Yes, it is quite common for them to die if not processed at the proper age.
Absolutely right, you got Cornish X. Process them quickly before they die on you! They will be delicious, though.
We have actual Tetra Tints, and I like them OK as layers. They are great layers of "tinted" large eggs. They are flighty like white Leghorns, though, and I think they are ugly--they have red leakage in their feathers and always look dirty to me.
The tinted eggs look lovely in the cartons, however, so I forgive them their looks.