Missing public key in transaction input I'm in the process of understanding scriptSigs of transaction inputs and encountered some transactions with inputs that seem to be missing a public key.

This is what I expect to see as a scriptSig. A signature and a public key.

ScriptSig: PUSHDATA(71)[3044022017e2af6e1308d431365deeb5739d41a909cf0d61a9c0e48f3ae5b0bd6544bfc5022066e73dd26d71d824552b034b322603cce8b936912b99f4f3df512e502bd7c11e01] 
PUSHDATA(33)[03d7b3bc2d0b4b72a845c469c9fee3c8cf475a2f237e379d7f75a4f463f7bd6ebd]


https://blockchain.info/tx/10857ad56f1695559562af8076aea4ccba625ba79a82f75e5658c0c2fa4336c0

However, I've encountered these type of scriptSigs as well. There seems to be no public key. What exactly is happening here?

ScriptSig: PUSHDATA(71)[304402204e45e16932b8af514961a1d3a1a25fdf3f4f7732e9d624c6c61548ab5fb8cd410220181522ec8eca07de4860a4acdd12909d831cc56cbbac4622082221a8768d1d0901]


https://blockchain.info/tx/f4184fc596403b9d638783cf57adfe4c75c605f6356fbc91338530e9831e9e16
That input spends a pay-to-pubkey output. The output it spends from contains the public key, so it is not in the input.