meso-, mes-, mesi-

(Greek: middle, intermediate; close to a center line; between)

Mesosauria
1. An order of extinct aquatic reptiles which is known from a single genus, Mesosaurus, characterized by a long snout, numerous slender teeth, small forelimbs, and webbed hind feet.
2. An order of small marine reptiles that lived during the early Permian period, roughly 299 to 280 million years ago.
Mesosaurus
A “middle lizard” was an odd, fresh-water dwelling reptile, not a dinosaur, that lived from the Late Carboniferous period to the Early Permian period.

It was one of the first aquatic reptiles whose fossils were found in South Africa and South America. Named by Francois-Louis Gervais in 1865.

mesoscale
In meteorology, of or having to do with atmospheric phenomena intermediate between microscale and macroscale.
  • Microscale is the smallest scale of meteorological phenomena that range in size from a few centimeters to a few kilometers while larger phenomena are classified as mesoscale.
  • Macroscale is the meteorological scale covering an area ranging from the size of a continent to the entire globe while smaller phenomena are classified as mesoscale.
mesosere
A community of plants which appears temporarily in an environment when there is a moderate amount of moisture in the soil.
mesosoma, mesosomia
1. A body of medium size or stature.
2. The middle of the body of some invertebrates; especially, when the phylogenetic segmentation pattern cannot be determined.
3. The middle portion of the body in an invertebrate; especially, the anterior portion of the abdomen in certain arthropods.
mesosphere
1. An atmospheric layer of the earth's atmosphere in which temperature decreases rapidly, located between the stratosphere and thermosphere.
2. The solid part of the earth's mantle lying between the asthenosphere and the core.
3. The atmospheric shell between about 28-35 and 50-60 miles (45-55 and 80-95 kilometers), extending from the top of the stratosphere to the mesopause; characterized by a temperature that generally decreases with altitude.
mesostasis
The most recently formed glassy or aphanitic interstitial material or the igneous rock with mineral components that are too fine to be seen by the naked eye which is located in the pores or between the crystals of an igneous rock.
mesosternum
The middle piece or body of the sternum (breast bone), a long bone running down the front of the chest, flat in many animals but ridged in most birds.

In humans, the top seven pairs of ribs are connected to it.

mesosthenic
1. Being moderately strong or of medium strength.
2. Strong in the median or the middle part.
mesothelioma
A disease in which cancer cells are found in the sac lining the chest, the lining of the abdominal cavity, or the lining around the heart.

Exposure can result in mesothelioma thirty or forty years later because of the long latency period of asbestos disease.

People who have been exposed to asbestos in a household environment, often without knowing it, or who have worked on jobs where they breathed asbestos, are in danger of being victims of mesothelioma.

mesothelium
1. The part of the mesoderm that lines the primitive body cavity of a vertebrate embryo.
2. The tissue derived from this part, lining the pleural, pericardial, peritoneal, and scrotal cavities of the body.
mesotherm
1. A type of plant that does not tolerate extreme temperatures and which flourishes in an environment with a moderate climate.
2. A plant favoring intermediate temperature conditions, with a minimum of twenty-two degrees Celcius (71.6 degrees Fahrenheit) in the warmest month and a range of six (42.8 degrees Fahrenheit) to eighteen degrees Celcius (64.4 degrees Fahrenheit) in the coldest month.
mesothermal climate
A temperate climate with moderate temperatures.
mesothermal, mesothermic,
1. Of or having to do with a moderate or intermediate temperature range; such as, of a climate, habitat, geological process, etc.
2. Relating to a hydrothermal mineral deposit formed at considerable depth (intermediate pressure) and in the intermediate temperature range of 200-300°C.
3. Living or thriving in a temperate climate; mesothermophytic.
mesothermophilous
A reference to organisms that favor or prefer to live in temperate zones.