Apex domains cannot have CNAME records.
Question and response
Question
dig tricorn.net. NS
Answer
tricorn.net. 4 NS ns018-0nuv06p80drjmq9d.0.d-53.info.
tricorn.net. 4 NS ns03.idc.jp.
tricorn.net. 4 NS ns02.idc.jp.
tricorn.net. 4 NS ns018-0nuv06p80drjmq9d.0.d-53.org.
tricorn.net. 4 NS ns018-0nuv06p80drjmq9d.0.d-53.jp.
Authority
The response has no authority records.
Additional
ns02.idc.jp. 4 A 64.56.165.91
ns03.idc.jp. 4 A 158.205.198.214
ns02.idc.jp. 4 AAAA 2001:d88:a001:7:64:56:165:91
ns03.idc.jp. 4 AAAA 2001:d88:a001:8:158:205:198:214
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0