proto-, prot- +

1. The outermost layer of cells in plants, forming the permanent epidermal tissue.
2. A thin outer layer of the meristem (growing plant tissue) in embryos and growing points of roots and stems of plants, which develops into the epidermis.

The upper half of the duodenum (the first part of the small intestine starting at the bottom of the stomach).

It is derived from the embryonic foregut.

1. In botany, a plant which grows on another plant, but which does not, like a parasite, derive its nourishment from it.

Many orchids and also some ferns and many mosses, liverworts, lichens, and algæ are examples.

2. In zoology, a fungus parasitic on the skin and its appendages or on mucous surfaces of humans and other animals, causing disease; a dermatophyte.

1. An immense concentration of gas and dust from which a galaxy is formed.
2. A mass of hydrogen that is sufficient to form or is already beginning to form a galaxy.
3. A cloud of gas in the early stages of its evolution into a galaxy.

A “first-jaw lizard” from Early Jurassic China. The name comes from Greek protos, “first, forward” plus Greek gnathos, “jaw”. Named by paleontologist George Gyorgivich Olshevsky (a.k.a. Dinogeorge) in 1991.

A first or original writing.

The male-like female that distinguishes one of the alternate generations of those trombidiformacarines (a group that contains the free-living water mites, as well as numerous plant and animal parasites, including the chiggers).

1. In botany, having the pistil or female organ mature before the stamens or male organs.
2. Frequently used as a synonym for progynous, but it is also used to describe the condition of being a hermaphrodite; that is, first being a female and then later, becoming a male.

A genus of fossil horses from the Lower Pliocene.

They had three toes on each foot, the lateral ones being small.

1. The period in any area following prehistory and preceding the appearance of coherent history derived from written records. It is a transitional time period between prehistory and recorded history, for which both archaeological and historical data are employed.
2. A time when non-literate aboriginal peoples had access to European goods but did not have face-to-face contact.
3. Periods during which historical documentation is fragmentary or not directly from the society being studied.
4. The period of 1250-1519 AD in Mesoamerica, which followed the Postclassic and ends just before the Spanish conquest (there are historic documents for this period).

1. Referring to or describing any of several hominoid primates regarded as being at an earlier stage of development than Homo sapiens.
2. Any primate or human species antedating modern man.

1. An ancestral language that is reconstructed by comparing elements in known related languages and creating a hypothetical form of their common parent language.
2. A recorded or reconstructed language that is the ancestor of another language or family of languages.

A very small lymphoid cell in the red bone marrow and in the spleen (a large dark-red oval organ on the left side of the body between the stomach and the diaphragm which helps to destroy old red blood cells, form lymphocytes or white blood cells, and to store blood).

1. Relating to, or characteristic of the very beginning or earliest part of the Stone Age.
2. Referring to stone implements selected according to the suitability of their form to a particular purpose without any definite shaping on the part of the user.

1. The study of origins and first things.
2. The science of the beginnings of things; for example, the mythology of primitive tribes.