11+ Intermediate Species Examples: Detailed Facts    

Intermediate species are the connecting links between two species which is the evidence of the evolution theories. In this article, we will learn about intermediate species examples and their characters.

Intermediate species show the connection between pioneer species and the climax community, demonstrating ecological succession, that change over time with some modifications. According to Charles Darwin’s evolution theory in “On Origin of Species”, all the species on earth share the same ancestors.

Several species are found in our diverse ecosystem; intermediate species are proved the theory of evolution that we all evolve from one ancestral.


Archaeopteryx is an intermediate species found as a transitional fossil in 1861, and it belongs to the late Jurassic period, which is around 150 million years from now. It’s a dinosaur with wings, but scientists first referred to it as Urvogel, which means “first bird “, but later they found similar characteristics to dinosaurs. Researchers found in their studies that this species can be a pioneer species or ancestors of modern birds. This fossil is now present in the London Natural History Museum.

Intermediate Species Examples
Transitional fossil of Archaeopteryx: A intermediate species between reptiles and birds from Wikipedia


A group of unicellular bacteria that’s filamentous lengths of cocci, gram-positive, and anaerobic. They also produce spores and are filamentous, which is similar to the character of fungus; hence they can be an intermediate species between bacteria and fungi.

Actinomyces: A intermediate species between bacteria and fungi
from Wikipedia

Balanoglossus (hemichordate)

Balanoglossus species is an evolutionary link between invertebrates and vertebrates. It’s a marine worm with gill slits, dorsal tubular nerve cord and notochord in the upper part of the body but the absence of a nerve chord. It’s found in shallow water, and William Bateson was the first who discovered these similarities and classified them as Enteropneusta.

Balanoglossus: A intermediate species between invertevets and vertibetes from Wikipedia

Chimaera (Rat or Rabbitfish)

This species of fish is a connecting link between bony and cartilage fishes. They are closely related to the sharks, but their upper jaws are fused to the skull, commonly known as rabbit or ratfish, ghost fish, and spookfish because of their structure.

Chimarera: A intermediate species between sharks and cartilage fish from Wikipedia


It’s a rare fish species found near the western Indian ocean. Coelacanths are closely related to lungfish and tetrapods (four-limbed animals). Its oldest fossils are over 410 million years old, most of the species are extinct, and some are preserved for the studies.

Coelacanth: A intermediate species between fishes and amphibians from Wikipedia


Ctenophores are sponges closely related to cnidarians and bilaterians. Its inner structure is more similar to cnidarians bound by inter-cell connections. They use cilia for locomotion, the same as sponges. And they are triploblastic, which means they contain a middle layer in their cell membranes, a common feature of bilaterians.

Pelagic-ctenophores: A intermediate species between Cnidarians and sponges from Wikipedia

Club moss

Lycopodiopsida is commonly known as club-mosses. There are homosporous, but some genera like selaginella and Isoetes are heterosporous. This species has a common feature in both groups; pteridophytes, as they have sporangia for reproduction and are bryophytes structure-wise as they lack complete leaf structure.

Lycopodiopsida: A intermediate species of pteridophytes and bryophytes from Wikipedia


Cycas is connecting link between Pteridophyta and gymnosperm. They produce sporangia (spores containing sacs) which is one of the characteristics of Pteridophyta. Like gymnosperms, they have naked ovules and naked seeds (seeds without fruit). And they produce cones which are a common reproductive feature of gymnosperms.

Cycas: A intermediate species between gymnosperm and pteridophytes from Wikipedia

Duck-billed platypus, Spiny anteater

Duck-billed platypus’s scientific name is ornithorhynchus, which is a connecting link between reptiles and mammals and is found in the south Australian zone. They are semi-aquatic egg-laying mammals. They are named in the red data book as a “near threatened” species by the International Union for conservation and nature in 2016 and trying to protect them.

Platypus: A intermediate species between reptiles and mammals from Wikipedia

Euglena (protozoan)

Euglena is a unicellular microorganism that is a connecting link between animals and plants. Similar to plants, they contain plastids for photosynthesis. And they have flagellum for locomotory action, a significant structure of single-cell animals. Typical habitats are freshwater, saltwater and moist soil.

Euglena diagram: A intermediate species between plants and animals from Wikipedia

Gnetum (gymnosperm)

They are advanced gymnosperm species and presented as a connecting link between gymnosperm and angiosperm. They possess gymnosperm and angiosperms characteristics—the features like vessel elements in the xylem show gymnosperm feature and have tree and climber appearances similar to angiosperms.


Viruses are the connecting link between living and non-living things. Neither do they have a complete cellular structure nor reproduce themselves without contacting any living sources. They become active in other organisms’ bodies, utilising host machinery to increase their numbers and cause damage rapidly. Viruses are composed of protein and nucleic acid DNA or RNA. They can survive many harsh conditions and live for a longer time. Viruses can infect bacteria, plants and animals.

Frequently Asked Questions:

What is an intermediate species?

Intermediate species are those species or fossils with standard features of differently classified species. All species are interlinked with each other in some portion.

What plants are intermediate species?

Intermediate species are shrubby plants, penial herbaceous plants, and some softwood trees. The plant has mainly been classified into five groups; some groups that alter the habitat and soil composition are linked to a complex tree structure.

What is an intermediate species evolution?

Transitional fossils are those intermediate species that were extinct already million years ago, present as a fossil and compared with currently known species.

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