Pinnipedia and Lepidoptera, Galliformes and Gruiformes-such was the daily fare of a remarkable 50-nation debate that ended here Friday.

Such scientific names of birds and animals were the only common language of delegates from Australia to Zaire, who gathered to update the Convention on International Trade in Endangered Flora and Fauna.

In was the second such meeting since the treaty to control the export and import of threatened wildlife was reached in 1973. Despite the reluctance of some large importing nations to clamp down ion the commerce, the convention reaffirmed and strengthened trade restrictions.

Two proposed amendments, which environmentalists charged would seriously weaken the convention, were defeated. One, a U.S. proposal, would have relaxed criteria for removing a species from the endangered list. Another, offered by Britain, would have limited trade restrictions to a specified list of animal parts and derivatives.

"Most of what was accomplished was in the nature of terrible things being prevented from happening," said Michael J. Bean of the Environmental Defense Fund.

The fund was in a coalition of 32 environmental groups, mostly American, that particapted in the convention here. The group, under the leadership of World Wildlife Fund president Russell E. Train, formed a powerful lobby that outnumbered and often opposed the official U.S. delegation. As former head of the 1973 U.S. delegation, and as chief of the principal funding group for international wildlife projects. Train carried weight with Third World nations.

By and large, the poorer countries that possess much of the world's wildlife sought to protect themselves from agressive consumer countries such as West Germany, Switzerland, Britain and Japan.

Brazil, Kenya and other nations complain that although they have strict laws against export of endangered species, developed countries sanction illegal smuggling by continuing to import cat skins, crocodiles, ivory, turtle and other products from them.

Last week, however, the convention set up an enforcement committee to deal with complaints between nations. "This convention accomplished quite a bit," said Kenneth Berlin, head of a U.S. Justice Department wildlife strike force. "It began, for the first time, to face difficult enforcement issues."

The environmental groups passed resolutions praising Liberia for a recent hunting ban and calling on Japan to ratify the treaty without exceptions for crocodile and turtle products. Japan, Mexico and Belgium are among major traders that have not ratified the pact.

While the pet and fur industries sent lobbyists, they were clearly outnumbered. The convention was "overly influenced by well-organized and well-financed" environmentalists, said Gary S. Kugler of the Associated Fur Manufacturers. "I'm afraid we lost this round."

The fur industry, together with state wildlife officials, had heavily pressured the U.S. delegation to lift trade restrictions on the bobcat. The Interior Department backed off after environmentalists threatened to sue.

Another controversy was resolved when the U.S. delegation, heavily lobbied by environmentalists, agreed to support a British proposal to control trade in all whale species. Some are not strictly endagered, the United States originally contended. But then U.S. delegates switched stands, saying they had been convinced by British information.

"People think these are purely technical meetings," explained Interior official Terry Wolkerstorfer. "Actually they're very political."

Environmental groups did not fight a U.S. proposal to downgrade Louisiana and Florida alligator populations from the endangered list to a category allowing trade. Nevertheless, John Grandy of Defenders of Wildlife predicted "a major battle" in the United States over whether to permit exports.

One of the conventions tense battles was over the vicuna. An endangered ilama-like animal whose soft wool commands high international prices. Killing was forbidden in 1969 and the vicuna now numbers 70,000 in Peru, Argentina, Chile and Bolivia.

A Peruvian proposal to allow limited trading in vicuna wool was supported by the United States and seemed certain to pass until the last minute arrival of Felipe Benavides, a flamboyant Peruvian conservationist.It would "sabotage" the treaty, he claimed, and the delegates agreed, 9 to 8, with most abstaining.