Thanks for the hints for 6dn Iguanodon. That solution made me realise I had 8 down wrong and a "review" of the possibilities led me to 6ac which I can just about fit into "bites" as Peterm said though I think it's a bit forced.
crawling wearily towrds the line here but there's no respite even at the end! Where do the inserts go in 23 ac; 34 ac; 4dn, 27 dn - and the first two letters of 21dn don't seem to fit....
The breaks are; 23ac FANS, 34ac DISPORT, 4dn CLANGERS. I have the answer to 21dn but don't know how it fits in. Can't get 27dn. I have ?ERT. Last space!