Pluggable transceiver assembly includes a transceiver body having first and second plug portions and a common base portion that joins the first and second plug portions. The first and second plug portions are separated from each other by an elongated wall-receiving gap that is sized and shaped to receive a receptacle wall of a receptacle assembly. The pluggable transceiver assembly also includes a communication sub-assembly having a transceiver substrate that includes first and second plug sections and a shared section that joins the first and second plug sections. The first and second plug sections extend toward a leading end of the transceiver body from the shared section to substrate edges of the first and second plug sections, respectively. The substrate edges include electrical contacts configured to engage a corresponding receptacle connector of the receptacle assembly.