A taxonomic <xref>subclass</xref> within the <xref>class</xref> <xref>Reptilia</xref> — the <xref>dinosaurs</xref>, <xref>pterosaurs</xref> and <xref>modern</xref> <xref>crocodiles</xref>.
User Defined Definitions
"used in former classifications to include all living reptiles except turtles; superseded by the two subclasses Lepidosauria and Archosauria"