2016 has been a banner year for boutique banks, but they all got shut out of Monday morning's mega-merger.

The Potash (Toronto Stock Exchange: POT-CA)-Agrium (Toronto Stock Exchange: AGU-CA) deal, expected to create a company worth $36 billion with $20.6 billion in revenue, went to bigger Wall Street institutions instead. The combination is expected to produce the world's biggest crop nutrient company.

Barclays Capital (London Stock Exchange: BARC-GB) and CIBC Capital Markets (Toronto Stock Exchange: CM-CA) advised Agrium, while Bank of America Merrill Lynch (BAC) and RBC Capital Markets worked for Potash on the merger. Morgan Stanley (MS) also pitched in, serving as a "joint financial advisor" to both parties, which is a bit of a rarity on Wall Street. Morgan Stanley did not respond to a request for comment about its role in the M&A deal.

Overall, the banks will earn between $80 million and $90 million for their efforts, said Jeffrey Nassof, director at mergers and acquisitions consulting firm Freeman & Co. Because both Potash and Agrium are Canadian companies, the presence of Canada banks RBC and CIBC on the deal shouldn't be much of a surprise.

So far in 2016, boutique banks have grown market share more than they did last year, which was a record year for dealmakers.

And boutiques' share of M&A has risen substantially since the global financial crisis, which saw many Wall Street rainmakers decamp from bigger institutions to work at smaller firms, where their pay can be substantially higher.

Boutiques like Ducera Partners, Guggenheim Partners and Qatalyst Partners have elbowed aside Wall Street stalwarts to earn the business of LinkedIn (LNKD), which earlier this year reached a deal to sell itself to Microsoft (MSFT), and roles in the ongoing tango between Bayer and Monsanto , as well. The flurry of activity for smaller banks is a bigger headache for Wall Street in 2016, in part because regulators are busting up big deals as never before.