Arambourgia is an extinct monotypic genus of alligatorine crocodylian from Europe. It was named in 1905 as Alligator gaudryi. It was made a separate genus Arambourgia in 1940. This was synonymized with Allognathosuchus haupti in 1990 (now known as Hassiacosuchus haupti), but later reassigned as its own genus once again in 2004. Arambourgia was likely to have been part of an early dispersal event of alligatorines from North America to Europe during the Eocene epoch. Arambourgia had non-serrated teeth and a deep orienirostral snout, unlike the flatter snouts of most other alligatorids.

Recent studies have consistently resolved Arambourgia as a member of Alligatorinae, although its relative placement is disputed, as shown by the cladograms below.

Cladogram from 2018 Bona et al. study:

AlligatorinaeCeratosuchus burdoshiAllognathosuchus polyodonAllognathosuchus wartheniNavajosuchus mookiArambourgia gaudryiProcaimanoidea kayiProcaimanoidea utahensisWannaganosuchus brachymanusAlligator prenasalisAlligator mcgrewiAlligator olseniAlligator sinensis Chinese alligator Culebrasuchus mesoamericanusAlligator mississippiensis American alligator Alligator mefferdiAlligator thomsoni
Ceratosuchus burdoshi
Allognathosuchus polyodon
Allognathosuchus wartheni
Navajosuchus mooki
Arambourgia gaudryi
Procaimanoidea kayiProcaimanoidea utahensis
Procaimanoidea kayi
Procaimanoidea utahensis
Wannaganosuchus brachymanusAlligator prenasalisAlligator mcgrewiAlligator olseniAlligator sinensis Chinese alligator Culebrasuchus mesoamericanusAlligator mississippiensis American alligator Alligator mefferdiAlligator thomsoni
Wannaganosuchus brachymanus
Alligator prenasalisAlligator mcgrewiAlligator olseniAlligator sinensis Chinese alligator Culebrasuchus mesoamericanusAlligator mississippiensis American alligator Alligator mefferdiAlligator thomsoni
Alligator prenasalis
Alligator mcgrewiAlligator olseniAlligator sinensis Chinese alligator Culebrasuchus mesoamericanusAlligator mississippiensis American alligator Alligator mefferdiAlligator thomsoni
Alligator mcgrewi
Alligator olseniAlligator sinensis Chinese alligator Culebrasuchus mesoamericanusAlligator mississippiensis American alligator Alligator mefferdiAlligator thomsoni
Alligator olseni
Alligator sinensis Chinese alligator Culebrasuchus mesoamericanusAlligator mississippiensis American alligator Alligator mefferdiAlligator thomsoni
Alligator sinensis Chinese alligator
Culebrasuchus mesoamericanusAlligator mississippiensis American alligator Alligator mefferdiAlligator thomsoni
Culebrasuchus mesoamericanus
Alligator mississippiensis American alligator Alligator mefferdiAlligator thomsoni
Alligator mississippiensis American alligator
Alligator mefferdi
Alligator thomsoni

Cladogram from 2019 Massonne et al. study:

AlligatorinaeAlligator prenasalisAlligator mcgrewiAlligator olseniAlligator sinensis Chinese alligator Alligator thomsoniAlligator mefferdiAlligator mississippiensis American alligator Procaimanoidea utahensisProcaimanoidea kayiArambourgia gaudryiHassiacosuchus hauptiWannaganosuchus brachymanusAllognathosuchus wartheniAllognathosuchus polyodon
Alligator prenasalisAlligator mcgrewi
Alligator prenasalis
Alligator mcgrewi
Alligator olseniAlligator sinensis Chinese alligator Alligator thomsoniAlligator mefferdiAlligator mississippiensis American alligator Procaimanoidea utahensisProcaimanoidea kayiArambourgia gaudryiHassiacosuchus hauptiWannaganosuchus brachymanusAllognathosuchus wartheniAllognathosuchus polyodon
Alligator olseniAlligator sinensis Chinese alligator Alligator thomsoniAlligator mefferdiAlligator mississippiensis American alligator
Alligator olseni
Alligator sinensis Chinese alligator Alligator thomsoniAlligator mefferdiAlligator mississippiensis American alligator
Alligator sinensis Chinese alligator
Alligator thomsoniAlligator mefferdiAlligator mississippiensis American alligator
Alligator thomsoni
Alligator mefferdi
Alligator mississippiensis American alligator
Procaimanoidea utahensisProcaimanoidea kayiArambourgia gaudryiHassiacosuchus hauptiWannaganosuchus brachymanusAllognathosuchus wartheniAllognathosuchus polyodon
Procaimanoidea utahensisProcaimanoidea kayi
Procaimanoidea utahensis
Procaimanoidea kayi
Arambourgia gaudryiHassiacosuchus hauptiWannaganosuchus brachymanusAllognathosuchus wartheniAllognathosuchus polyodon
Arambourgia gaudryi
Hassiacosuchus hauptiWannaganosuchus brachymanusAllognathosuchus wartheniAllognathosuchus polyodon
Hassiacosuchus haupti
Wannaganosuchus brachymanusAllognathosuchus wartheniAllognathosuchus polyodon
Wannaganosuchus brachymanus
Allognathosuchus wartheniAllognathosuchus polyodon
Allognathosuchus wartheni
Allognathosuchus polyodon

Cladogram from 2020 Cossette & Brochu study:

AlligatorinaeCeratosuchus burdoshiHassiacosuchus hauptiNavajosuchus mookiAllognathosuchus polyodonAlligator mcgrewiAlligator prenasalisWannaganosuchus brachymanusArambourgia gaudryiProcaimanoidea kayiProcaimanoidea utahensisAlligator olseniAlligator sinensis Chinese alligator Alligator mississippiensis American alligator Alligator mefferdiAlligator thomsoni
Ceratosuchus burdoshi
Hassiacosuchus haupti
Navajosuchus mooki
Allognathosuchus polyodonAlligator mcgrewiAlligator prenasalisWannaganosuchus brachymanusArambourgia gaudryiProcaimanoidea kayiProcaimanoidea utahensisAlligator olseniAlligator sinensis Chinese alligator Alligator mississippiensis American alligator Alligator mefferdiAlligator thomsoni
Allognathosuchus polyodon
Alligator mcgrewiAlligator prenasalis
Alligator mcgrewi
Alligator prenasalis
Wannaganosuchus brachymanusArambourgia gaudryiProcaimanoidea kayiProcaimanoidea utahensisAlligator olseniAlligator sinensis Chinese alligator Alligator mississippiensis American alligator Alligator mefferdiAlligator thomsoni
Wannaganosuchus brachymanus
Arambourgia gaudryiProcaimanoidea kayiProcaimanoidea utahensisAlligator olseniAlligator sinensis Chinese alligator Alligator mississippiensis American alligator Alligator mefferdiAlligator thomsoni
Arambourgia gaudryiProcaimanoidea kayiProcaimanoidea utahensis
Arambourgia gaudryi
Procaimanoidea kayiProcaimanoidea utahensis
Procaimanoidea kayi
Procaimanoidea utahensis
Alligator olseniAlligator sinensis Chinese alligator Alligator mississippiensis American alligator Alligator mefferdiAlligator thomsoni
Alligator olseni
Alligator sinensis Chinese alligator Alligator mississippiensis American alligator Alligator mefferdiAlligator thomsoni
Alligator sinensis Chinese alligator
Alligator mississippiensis American alligator Alligator mefferdiAlligator thomsoni
Alligator mississippiensis American alligator
Alligator mefferdi
Alligator thomsoni

Palaeoecology

Based on its unusual anatomy and it having been found in karstic settings, A. gaudryi occupied an ecological niche analogous to present-day juvenile and dwarf crocodylians.