Apex domains cannot have CNAME records.
Question and response
Question
dig tidc.telus.com. NS
Answer
tidc.telus.com. 5 NS dns2.tidc.telus.com.
tidc.telus.com. 5 NS dns1.tidc.telus.com.
Authority
The response has no authority records.
Additional
dns1.tidc.telus.com. 5 A 209.202.110.120
dns2.tidc.telus.com. 5 A 209.202.110.121
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0