I'm looking for a term to refer to an alien species that may evolve differently and have some unique and radical features, but still shares some of the most basic features of earth species. I'm looking for a certain degree of specificity for scientifically accurate discussions.

The most obvious term I'm sure anyone would think of is 'humanoid', but this is far too restrictive. The odds of any alien species evolving to look so human as to be considered 'humanoid' is quite unlikely. Actually the odds of an 'earth-like' species is unlikely too, but still I want a word that leaves open a much large category of species. What I want to exclude with such a word is species that are so utterly alien as to be difficult to grasp for humans at all. Thus I want to refer to species that could be vastly different, but imply at least enough similarity to something from earth to be comprehended by humans.

At a minimum this means carbon-based, but carbon-based is still a very wide window. I'd like to imply some aspects shared by most earth species likely exist, not necessarily requiring all of them. Aspects like multi-cellular bodies with specialized organs, possessing of genetics encoded in some DNA-like manner, Some form of genetic exchange like sexual-reproduction (not requiring traditional male and female), brain-like structure for thinking and driving decision-making (not necessarily sapience or high intellect) etc. Put another way, anything that could realistically be seen evolving from creatures that were very similar to earth's primitive early multi-cellular organisms, even if that evolution went in a very different fashion from earth.

Is there any good word or phrase to communicate this concept beyond earth-like. The phrase earth-like I fear may be a little too restrictive itself, implying perhaps too close a similarity to current living earth creatures and ecosystems and thus not leaving open a little more room for novelty in creature design while keeping to the basic structure.

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    I would focus on the features of the environment that make a creature earth-like. Oxygen levels are one example. "An aerobic organism or aerobe is an organism that can survive and grow in an oxygenated environment." Wikipedia
    – TsSkTo
    Dec 17, 2015 at 18:52
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    How about tellurian? (like solarian, lunarian etc.). It is from Latin tellūs (earth) and Tellus is the goddess of the earth in Roman mythology also.
    – ermanen
    Dec 18, 2015 at 1:00

4 Answers 4


It would be a coinage, but I would suggest combining terrestrial or terran with the suffix -oid or -id meaning basically “looks like,” as in your humanoid or its taxonomic equivalent hominid; thus terranoid or terrestrid. (Perhaps not terranoid, as rather too close to a more familiar term.)

  • On the line of suffixes one could look up Greek and Latin roots. -ish can somewhat mean "resembles" so you could add terrish and a slew of other words to your list.
    – Neptunian
    Dec 18, 2015 at 9:51

I think terrestrial may suggest the meaning you referring to:

  • of or relating to the earth or its inhabitants.

  • pertaining to, consisting of, or representing the earth as distinct from other planets.

The Free Dictionary


Non-Boskonian, referring to E. E. Smith's universe where life in our galaxy arose from drifting spores of the parent race of Arisians, which gave rise to races of radically different biologies, but who were all, fundamentally, good guys. As opposed to the evil forces of Boskone, which stemmed from some distant, horribly different portion of the space-time continuum.


Consider eukaryotoid, that is like a eukaryote. A eukaryote is any (earthly) organism made up of one or more cells containing organelles enclosed in a membrane, among which the nucleus with the genetic material. Eukaryotes includes all animals, plants, and fungi.

The adjective eukaryotic exists, but you may prefer eukaryotoid to convey the idea that the organism is not quite like the earthly eukaryote. You could use combinations such as higher eukaryotoid or complex eukaryotoid to stress that the organism in question is multi-cellular, or neural eukaryotoid to stress they have something we could call a nervous system.

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