Solenodon — the slotted-tooth mammals

Anatomy and adaptations

Solenodons have a flexible rostrum, strong limbs for digging, and coarse fur. Their dentition includes long incisors with a longitudinal groove; saliva from modified salivary glands travels along these grooves when they bite. This adaptation helps subdue invertebrate and small vertebrate prey. They retain skeletal and cranial characteristics that are considered primitive for mammals, such as certain skull and jaw features that echo early mammalian forms.

Taxonomy and species

Only one living genus, Solenodon, remains. Two extant species survive: the Cuban solenodon (Solenodon cubanus) and the Hispaniolan or Haitian solenodon (Solenodon paradoxus). The Hispaniolan solenodon occupies a variety of habitats across the island of Hispaniola, from lowland dry and moist forests to montane pine and cloud forests. Both species are island endemics and have very restricted ranges compared with widespread small mammals.

Behavior and diet

Solenodons are primarily insectivorous but will take a range of animal matter, including insects, worms, snails, and occasionally small vertebrates. They forage at night, probing leaf litter and soil with their elongated snout. Their sensory adaptations and nocturnal habits make them secretive and difficult to observe. They dig burrows, use natural rock crevices or shallow nests for shelter, and typically raise small litters.

Evolutionary history and fossils

The solenodon lineage is ancient and was more widespread in the past. Fossil relatives and similar insectivorous mammals are known from earlier epochs. Some paleontologists have suggested links to North American Oligocene groups and genera such as Apternodus, and fossils from the Oligocene and later deposits have been examined for comparisons. Two additional solenodon species are described from the fossil and historical record and are thought to have become extinct during the Quaternary.

Conservation

Both surviving solenodon species are of conservation concern because of limited ranges, habitat loss, and predation and competition from introduced mammals such as dogs, cats and mongooses. Conservation work includes habitat protection, field surveys, community engagement, and captive-care research. Because solenodons represent a relict branch of mammal evolution, they are a high priority for researchers interested in mammalian diversity and evolutionary history.

Further reading and resources

Specialist reviews, field reports and taxonomic summaries provide the best current information. See general overviews on venomous mammals and nocturnal specialists for context: venomous mammals, lists of nocturnal mammals, the family entry at Solenodontidae, genus summaries at Solenodon, and discussions of primitive traits at primitive mammal characteristics. Regional biodiversity accounts for Hispaniola include conservation status and habitat descriptions, and paleontological literature references include work relating to the Oligocene and proposed relatives such as Apternodus. Historical accounts and Quaternary records are noted in reviews of extinct Caribbean mammals (Quaternary extinctions).

• Distinctive trait: grooved, slotted lower incisors linked to venom delivery.
• Distribution: island endemics of the Caribbean, mainly Cuba and Hispaniola.
• Significance: a living relict lineage that informs understanding of early placental evolution.