Monotremata

species profile - NatureBase (Western Australia)

dichotomous key - WikiBooks

The American Zoo and Aquarium Association (AZA) - the Marsupial and Montreme TAG is composed of a group of experts responsible for making recommendations for AZA institutions regarding species within this taxonomic group of animals. These recommendations are published in the Regional Collection Plan (RCP). This includes evaluations of the needs for captive breeding and space availability for each species within the participating institutions

this action plan is a strategic document undertaken by scientists to review the status of a defined group of related organisms. They review the conservation status of major Australian taxonomic groups against IUCN categories, identify threats and recommend actions to minimise those threats - Australian Department of the Environment and Heritage

skull morphology, CT images - University of Texas at Austin

skull morphology, CT images - University of Texas at Austin

an independent organisation dedicated to conserving the platypus and its freshwater habitats

UCMP Berkeley

University of Michigan Museum of Zoology

link compilation