Sorry, I don't know what type of cucurbit it is.
Inedible? Only way to know is to let it ripen and harvest only once the stem to the fruit has dried out - farmer background in my family. Harvest before then and that can have the fruit unpalatable as it hasn't reached absolute full maturity. It is also when the pumpkin will store for longest.
Did it start bright yellow in colour? There are so many different types of pumpkin, and many start a different colour to when they reach maturity. Gonna be a waiting game. I'm keen to find out how your pumpkins turn out to be
I've got pumpkin vines growing in my suburban backyard, butternut and 'halloween' types. I have them grow over the back awing and chook pen and this helps tremendously to make the back verandah cooler in summer, and shades the chooks. I've now got pumpkin fruit growing over the verandah. One good year I've harvested 24 pumpkins from the on top of the awning, the smallest was 2kg. The halloween one started dark green, and changed to bright orange not long ago. But the stem is still very much green so not harvesting it until the vine has dried out. The butternuts I grow are as sweet as honey! The halloween one, I have no idea how it'll be to eat, but I'll find out in a few months time. I scavanged the seeds from a pumpkin last halloween. Huge vine! No one I've asked knows anything about these pumpkins. Even the fruiterer knows nothing about them,

. There are several types of 'halloween' pumpkins, some of which are unpalatable, but others not. Oh well, only one way to find out which this one is!
EDIT: Even is unsure about the fruit, you can still eat the flowers - same way as zucchini flowers. YUM!!! And pumpkin vines produce a damn lot of flowers.